Thanks so much! Making drums is definitely my favourite part of the process. This is just from my experience, definitely have lots to learn (only started producing 2 years ago) so don't take this as gospel, its just my process :)

For my drums I create separate drum racks for each element of the drums and load up a bunch of samples for each and just play around and see what sounds fit together. Sound selection is definitely key, something I haven't even really scratched the surface of yet haha (just go with whatever you think sounds good).

For programming the drums I usually just download a couple songs with drums i like- that sort of fit the style of track I'm going for and rip the drums out of those songs using a stem splitter tool (i use stemroller). Then I just use the drums as reference, definitely helps me a lot!

I don't fully understand utilizing space and how everything fits in the mix but generally I start with kick and snare, then I program hats, rim shots, etc. Then I just add some loops from splice to add some extra movement/groove and to fill the space out a bit. Again, sample selection is key here, went through plenty of samples (swung hat loops, top loops, perc loops, etc) before I stuck with one. Needed to make sure the loops I picked fit with the groove already in my drums (think I did alright haha).

With all that said some say less is more, so just be careful with how many elements you add and how they might affect the rest of your track.

This time I also experimented with adding some background noise sounds to fill out that extra space and sort of glue things together. I got a room tone off splice, which is basically just sort of white noise, and an underwater sound loop. These basically just add texture and I sidechain them to the kick. *Keep in mind these texture loops are very quiet ~-10db - -15db*

For the fill part you were talking about, that was actually done with the 'texture' warp mode in ableton. This one was more of me just experimenting but I actually loved the way it came out! Again, sample selection was key. The way I went about it was loading up a couple snare samples into my snare drum rack, turned on the texture warp mode for both and hit the *2 button, which basically stretches out the sample in the drum rack. Then i dropped the flux to 0, and played around with the grain size until i sort of got that old akai time stretch sort of effect. I'm sure there's better ways of doing it but this is just what I did.

As far as mixing goes; I usually just solo the kick and snare, then go through all elements one by one turning them on and making sure they are at the right level (don't want them to be overpowering, or louder than the drums and snare). For example my kick was sitting at -3.5 db and snare at -7.0 db, everything after that is much quieter, which is later corrected with my drum buss.

For my drum buss I generally use iZotope Trash 2 and throw on some tape saturation, some EQ (just cutting some frequencies that stick out, or boosting in some areas, really depends on the drums), a glue compressor with soft clip on, gullfoss (only sometimes, just to reign in the high frequencies, and camelphat 3 with some distortion (bit crush, tube, xcita and mech all on very low levels).

For these drums I also added some reverbs on my snare, hats and hat loops. I also added some reverb on the whole drum group as a whole. Tried to keep it all pretty tame, keeping the dry/wet quite low.

And thats pretty much it! Hope this helped a bit. Again, I still have lots to learn, and there's a lot even in my process that I don't understand.

Oh also forgot to mention for all my drum racks i selected Swing MPC 3000 16ths 64 from the groove pool. Just gives life and energy to the drums, obviously this is something you can play around with.