You say you're "run first." What type of run concepts do you like? Power? Inside zone? Stretch or outside zone? Counter?
To really set up a "scheme" I suggest picking a couple of these concepts that you really like. Let's start with Power. You can run it from
21 personnel I-form or
11 personnel shotgun and any formation in between. Most power run plays will be for your RB but you could also run
QB power or run it with a
read element. Running the same concept for different players, out of multiple personnel, and different formations keeps things simple for you on offense but looks complicated to the defense. Then start to add constraints to those plays and place these as your audibles. This could be
playaction passes or a
weak side run. So you have the base concept you want to run, you can run it out of multiple looks, and you have audibles to go to if the defense overcommits.
Now do the same thing for whatever pass concept you like. You said you use a lot of underneath crosses. Look at the
Drive concept. It starts with a shallow cross, normally with a deep-in behind it. It can be run from 5-wide spread sets, bunch sets, 2 TEs, 3 TEs, etc with always the same read by the QB. Then for each pass play be able to audible to a pass play that attacks a different area of the field, a draw and a screen.
Then do the same thing for another run concept and another pass concept and so on. The total number of concepts you use can be up to you, as well as the number of versions of those concepts.