So, you want to write better songs in 2021. I get it, I too have felt the urge to improver my songwriting ability many times throughout my music career (and still aim to improve!).
Sadly, one of the easiest ways to improve at such a task is through, yep you guessed it, repetition. Just keep writing songs; good, bad and everywhere in-between. I personally feel like the quality isn't as important as the reps, since you want to be able to flesh out an idea quickly when inspiration kicks in at any given moment... To do this requires practice, and lots of it.
Okay so given that you are currently writing lots of songs, or have written lots of songs, or are planning on writing a lot of songs - what are other ways to improve? Great question.
I've personally found it incredibly useful analysing other songs and artists that I like to see what kind of conventions they're employing (such as song structures, types of melodies, complexity of melodies, chord progressions etc etc etc), and then trying to use those in my own songs. At first it'll feel contrived and weird, but with time those techniques that work for you will slowly become more natural and less of a conscious effort.
Another excellent strategy is starting a song with a particular technique / vibe / bpm / key (or whatever other constraint you like) in mind. It becomes a challenge, and shows you how you can use constraints to actually be more creative. All of this is fairly counter-intuitive, but trust me it's the good stuff that'll help you push forward in your ability.
My last little trick for today, which also does somewhat link to the above points, is to attempt to recreate a song. This perhaps applies more to arrangement and production skills, but trying to recreate a song (or at least the vibe but with different chords and melodies) can be another great way to get out of your current habit-loops and break free into a different kind of thinking. Definitely worth a shot.
Anyway, weird rant over (not sure if I should be writing blogs lol but here we are). You can purchase beats on my store Rollo Beats or check out my mixing and production services, if you so desire.
Have a good one!