I do a few things. In the past 8 months I’ve gone from A1+ (lots of vocab), to C1 with academic writing, and the only thing keeping me from C2 is that I’ve literally not heard so much.
What I would do from your level is Practice Makes Verb Tenses for grammar (youtube videos exist to teach each grammar skill, if you want it heard auditorally too.) Video, workbook, video workbook.
Netflix has been my number 1 tool in learning Spanish. Don’t feel ashamed to use English subtitles (I had a few people try to language-shame me, they can go living in a world where they speak 1 language but do so through “purist” means.) I watched an 80 episode show, the first season I was A1/2 and was matching the Spanish sounds with English words. Season 2 I watched in Spanish subtitles (reading practice) but there was no way I was reading to a foreign language and listening to it. So I “read” TV in Spanish. After the reading improved, I switched back to English to practice my listening. Then I hid the English subtitles, and now I turn off subs and use them as an Answer Key when necessary (or when my brain is tired, I’ll revert.) The point is, 150 hours of glorious tv watching later, I can watch an hour long episode without subs and I understand it!
That’s listening / reading practice.
For talking, I would do one of two things, or both. I would use HelloTalk or email penpal sites or language exchanges to gain natives to speak to. You say you’re B1, make sure you have a decent command of preterite, imperfect, present, conditional, and “voy a…” That’s all you really need to speak your mind in a conversation. At that level, just talk and talk and talk with anyone who will let you. I like Italki, and the Latin American teachers are very affordable (there’s little difference, since you are British and likely learning Spain Spanish just let them know, and they’ll make sure to respect the seseo sound.)
I’ve studied almost exclusively with L.A. folks, but even just Velvet and Chicas de Cable was enough to be able to make that Spaniard accent sound, know the difference in key phrases, understand the vosotros, etc.
I have a language exchange with some Spaniards. I’ve found them to be elitist about their Spanish vs. LA Spanish, but they talk to me just fine, don’t hate on my accent, then I will say something small like “papas” or “computadora” and they flip out. So, the point being, LA Spanish teachers are good enough, the divide so small, and a more serious study of Castillian Spanish will cover the gap. (I’m just trying to bridge between South American and Mexican Spanish, and the Argentinian podcasts I listen to aren’t helping the matter - my accent has gone bonkers since I fell in love with the word “esha” (ella).
Netflix, Practice Makes Perfect Verb Tenses (and Irregular Verbs). Regular Skype meetups with native speakers. Possible tutoring like iTalki.
After all that, just start living your life in Spanish. I talk to myself in Spanish. I have to convert back when talking to others (poor spouse!) My phone is in Spanish. Duolingo became my toy game on it. All my music is Spanish-speaking. I have financial podcasts in Spanish, Game of Thrones podcast in Spanish (Argentinian, be warned), etc.
Try to put in two hours of day of conversation. Write all the words you’ve learned down, you’ll go through a process of not knowing it, still not knowing it but having heard it once, not knowing it but able to pick it out of a line-up, using it terribly four or five times, then using it like a pro.
Websites that are amazing.
Linguee has extra contexts of words used. If you want to see a word in use 8 times (to bump it from never seen it to “seen it 8 times”), go there for native examples.
SpanishDict has audio pronunciations.
I’ve mentioned iTalki, you can use it to find shared partners even if you’re trying to learn for free.
Lengalia has been like a fancier, more highly priced version of the Verb Tenses book. I would not recommend it for cost to ratio’s sake, but yes it is something that teaches me, and I’m someone who wants variety in my studying.
Youtube has been amazing. There’s so much free content, both educational (grammar), and native content - songs with the lyrics posted, documentaries, interviews.
Late Motiv is the name of the late night show in Spain. If you want to hear conversational Spanish, you could watch all those from Youtube.
You can start reading too. I liked “reading” (deciphering) native websites. BBC Mundo is good for beginners. El País is good for B2+, and feels like the daily crossword [as in, there’s always a fancy word or two I need to look up.] There’s so many opinion pieces and newspapers online; start reading your news in Spanish (or at least a few articles in your spare time.)
There’s an app on the iPhone for Ecuadorian radio stations. Only the Voz de Tomebomba works for me consistently as a Spanish-speaking station. But yes, find some Spanish radio, both talk radio or music radio, and learn to love the advertisements. Car sales! Flu season! Football team commentary.
I like to track my progress. I have a hours of TV watched tracker (otherwise I feel I “wasted” my time, even though Netflix is the most useful thing second to Spanish conversation with natives.) I have an hours-talked tracker. I have a workbook tracker. A writing prompts tracker. (Oh there’s a thing called “365 puntos para escribir” if you want creative writing prompts in Spanish)
Some days I’ll feel like I got nothing done in Spanish, but that’s because I swapped successfully through so many things that it felt easy and effortless. When your Siri is in Spanish, you know you’ve made some progress. When you watch a tv show entirely in Spanish, and you talk for four hours with natives, you’ve made progress. And yet, you’ll feel like it was none, because it gets insanely easier once you start hitting B2+ and C1. Now, I’m living my life like a Spanish native 14 year old. Don’t know all the hardest vocab words and I read slow, but I can submit an essay about advanced topics and outexplain the natives on topics outside their wheel house.
Over time, you lose sight of the journey (like a ship off the coast, close to the final destination, but adrift in the Atlantic not knowing when land will come.) For this, I recommend tracking by hours studied. I agree with the estimates, I feel like 1,000 hours is good progress. Maybe 700 of “official hours only”, but Netflix and music and podcasts about Game of Thrones are also studying.
So integrate your life into all Spanish, all the time. Find new Spanish hobbies - like football matches in Spanish commentary, new Spanish tv shows, etc. Find Spanish “friends” aka the people you’ll talk to more than your In Real Life friends.
Oh, other oddly helpful website, Google Docs. Can type on my phone (change all your keyboard functionalities ASAP on phone and computer. I just press a button, and I got all my áñéíú characters on my phone. With Google Docs, I can type up a writing prompt, and then share it with whichever native “friend” is willing to look at it. We can correct the grammar in different colors.
Find people from different countries, or different cities at least. Also, find a lot of speaking partners because you’ll not find one that’s perfect for all topics. I have irreverent ones (they’ll tell off-color jokes, giving me flexibility to learn curse words or hear real life stories), I have devoutly religious ones (and what is Latin America without Catholicism), I have ones I can giggle and chat with, I have ones who will correct my every grammar mistake (needed at times), I have ones in my profession so we can talk “shop talk” about day to day life. It’s just nice to have the voices of 7 or 8 people forming your speaking abilities, it’s like being a kid and learning to talk from mom, dad, grandma, teacher, tv, school friends.
Find Spanish comedy, too. Like I said, Late Motiv is an option for Spain. Latin America has comedy specials on Netflix, and the scripted comedy Club De Cuevos, which is super funny (and dirty.)
Learning Spanish is living real life, so structure it so that it’s fun, and ubiquitous. I even “study” Spanish when I do the dishes and on my commute. And by “Study”, I mean podcasts of interesting topics playing, So, I’m learning Spanish, and it sure doesn’t feel like “studying” in the old, boring way.
Keep track of daily progress. Motivates you, and helps you see your progress, because this goes by so quick. Maybe record your speaking voice and write a short prompt now, so you have something to look back on when you’re C1+, feeling tired, and realize, aww how cute, you used to write and speak like a 1st grader. (Except 1st graders speak better…) Makes reading 80 pages over 8 hours feel like a miracle and a celebration, in month 5.