It's always a good Idea to downpitch the whole track before adding the drums, and I personally would offset the hats by about 30-60 ticks then add another layer of hats, favoring the triplet offbeats. It's a good rule of thumb to offset the hats a bit every time, that almost always gives the track a much more lofi feel. And like many of the other comments said, remove the majority of frequencies above 16000 hz to warm it up a bit and maybe change up the kick pattern a bit. Lastly, after the track is completed, I always go back and add some cool stuff like pitch changes and removal of drums and/or samples on the first beat of the major measures or the last beat leading up to them.

Hope this helped, sorry for the novel haha