Aside from all of the details of technique and usual things we ought to be mindful of in our aikido practice, I have three things in particular I'm trying adhere to on my own agenda.
1.) Paying attention through the whole waza.
This is funny because you think you'd naturally have to pay attention in the middle of a technique, but most of the time actually, I'm somewhere completely else, or just blacked out in the middle of techniques, whether I'm the tori or the uke. I've been trying to be careful of this for a while, and so before a technique I'll say, "OK, gaijin, just try and pay attention through the whole technique." Then two seconds into it I'm thinking about a beer or the next episode of Game of Thrones (awesome new HBO show ... heard of it?) OR, I completely blackout in a way and just find myself on the ground after someone throws me. So, I've found two things that help with this: one is to breath through the technique and not hold your breath, and two is to keep your eyes open. Often times I might hold my breath and close my eyes ... but then I'm somewhere else and not doing as good a job as I could.
2.) Executing good zanshin.
My interpretation of zanshin here could be considered a kind of follow through ... but lasts even beyond the physical movement. It means having a strong final stance after the move or throw, and continuing watching the opponent, and possibly continuing moving towards him for another attack. This is something that my sensei doesn't bug us about very often, but if you want to have it, you gotta be paying attention. All of the students in my dojo certainly know about it, but most people never show it, and sensei doesn't point it out. But, I feel it makes my technique and intent a hundred times better ... so I'm trying to pay attention to this point. Also, this isn't just while you're the tori, but also when you're being thrown as the uke. Too often I find myself coming back up in a sit-up-like action which puts my head right in front of someone's knee. Be mindful of this all the time.
3.) Trying to feel my partner's heartbeat.
This is kind of a weird one, but one that's really got my attention and is fun to try. When I grab someone for a wristgrab, I'll try and secretly feel their heartbeat through the technique. It's kind of tricky and I'm not sure if it helps anything, but like I said, fun to try. I first noticed it with one of the very skillful higher dans who is a fairly petite girl, I grabbed her wrist and felt her heartbeat and the first thing I thought of was the small beatings of a swallow's heart.
So, yeah ... I think my aikido will improve if I can do these three things consistently.