Hey guys, I have been meaning to improve my theory but unsure where to go from here. I know the diatonic scale and the major/minor scales that are within it, the steps/intervals that make up the major/minor scales, how to comprise a major/minor/diminished scale, how to create a harmonized major/minor chord progression etc but that is where it stops. Where should I go from here? I have only touched on things like "The V chord is good for a resolve"(just an example, that is probably wrong lol)I have memorized the harmonic and melodic minor scale on the fretboard but do not know how to compose chord progressions for them and I'm sure there is a whole heap else I need to look into. I do not know how to make a chord progression sound "Dorian" or Mixolydian for example. Any help is much appreciated. Any intermediate guitar books or ebooks that would help?

ESP Horizon NT II
ESP Horizon NT 7
ESP Horizon FR II
You should start looking at pieces of music and trying to make sense of them in the context of what you already know. Knowing about scales and chord construction without knowing how they work in actual pieces of music is a bit akin to knowing about iambic pentameter without ever having read Shakespeare. It's not until you see the concept come alive in the actual work of art that you can really appreciate it's use.

There is no strict method for composing harmonic progressions. You just have to do. The more you do the more you learn.

What you should learn next depends on where you want to take this.
I strongly encourage you to get "Songwriting Secrets of the Beatles" by Pedler, even if you're not a big Beatles fan. This book takes you through a ton of concepts (starting with the role of that V chord!) and gives you tons of practical examples. It really helps you hear what's going on.

And that's the other thing you need to do. You need to listen. It is not enough to know concepts. You need to be able to hear them in practice. So work on your ear.

And don't worry about modes just yet.
Yea Songwriting Secrets book is money in the bank

What's great about it is that its applied to rock/pop music and most theory books refer to common period examples. I have yet to find a better applied theory book. You get a clear focus on why things work in context