depends on how you being taught in aikido. there are a number of principles that govern time and space which might help. however, it depends on how you are being taught in aikido. this video gives you some ideas http://www.youtube.com/watch?v=MsZk7Eha1Us
some would say that's not aikido. you can try to tell that to him. one principle - irimi first, irimi later, and when you are done irimi some more.
oh ya! did i mention irimi?
lets see if i can paraphrase Saotome sensei. "hands feet no enemy. enemy enemy" *with the accent* when you go after a snake, you don't go after the tail or the body, you go after the part that controls the body and the tail, i.e. the head or more correctly, the mind that controls. have you thought of sparring naked?