Is there another way to do it? I used to program in GP before I decided I hated tabbing as I wrote, so now I just compose drum parts in the piano roll. Yes, it is a lot of clicking.
I'm also an EZ Drummer user. I've bought like 30 MIDI packs so my workflow is a bit different. I like the Toontrack MIDI pack route because things that work well together are bundled together and I find the search tab pretty handy. If I need a fill that's snare or tom centric, you can select those filters and check out the results. There are cheaper options for EZ Drummer compatible MIDI libraries (Ugritone has many options but I have yet to try them) but, unfortunately, they don't integrate into the strongest features of EZD like the search functionality. You can import these 3rd party MIDI libraries but they will show up as a bulk list of MIDIs under the "User MIDI" section. It woyuld be awesome if they allowed 3rd party libraries the ability to install with a folder structure like the Toontrack libraries but such is life.
So I use the Toontrack libraries as my starting point and then I do variety of things to personalize the drums- add/remove individual hits & accents, split a pattern short (most Toontrack patterns are 2 bars long) & add a fill before starting the pattern over, and adjust velocities as others have detailed. Tap2Find was mentioned- I haven't used it very much. I can see how it would be useful but I seem to have trouble inputting my pattern in sync with the click track it offers (like a latency effect but whatever). What it does is, based on the rough snare/kick pattern that you provide, it searches through your MIDI library for patterns that match the input pattern. Again, it can be a quick way of finding patterns in the ballpark of what you want.
The last thing would be to add EZ Drummer into your Reaper project as a multi-track setup as shown in this video:
The main reason I do this is to have more control over the levels of various components of the drum set.
I used to split all of my EZ/SD channels into individual tracks, but I found that any of my "mixing" edits would inevitably just make it sound shittier than it did using the stock house mix out of the kit. :lol:
I don't mess much with it, TBH. Mostly, I remove room ambience to make the drums sound tighter with the rest of the other instruments or maybe reduce the "strength" of some part of the drums in the mix rather than editing velocities (hi-hats, etc)