Selin: I wonder.. do you just do kata dori, or is there some sort of follow up attack? we usually do katatori-menuchi which gives you a lot of energy to work with, but of course these other variations need to be studied as well.
From katadori menuchi more variations are possible. for example ikkyo and nikkyo can be tori-te or uchi-te depending on whether you grab the striking or gripping hand.
Apart from that I second the emphazis on atemi. Being so close it is necessary to be very precise in the way you use atemi to close the gap and to keep uke out of balance.
This might inspire you: