I always try to train in a "martial" mindset and like to make my aikido as effective as possible. I try as many variations as possible and use lots of atemi. I practise Kaeshi-waza whenever I can to learn the strong and weak points of a technique. When I attack an experienced aikidoka I expect to hit them if they dont move and vice versa, if they/I dont have a guard up then they/I get hit by atemi too.
The ways that I would practise certain aikido techniques in a more Martial/combat form are like this:
Ikkyo: Smash the elbow with a strike.
Nikkyo: Break the wrist. More of a projection technique.
Sankyo: Break the fingers and wrist. Just crank it on.
Yonkyo: Break the fingers/elbow.
Shihonage: Pull it uke's arm down onto your shoulder breaking the elbow, pulling out shoulder.
Kotegaeshi: Crank it on and twist into shihonage sort of, can break wrist and or rip tendons.
Iriminage: Break Uke's Neck.
kaitennage: Break Ukes arm, Knee them in the face, Break the neck.
Tenchinage: Break Ukes jaw/nose/collar bone.
Thats just the nine basics but obviously there are a lot more nasty variations of a technique that you can gain an understanding of. Those are the basic variations as I like to think of them. This is what these techniques were originally designed to do for "battle field" use or whatever you want to call it. What we practise in the dojo is the more art side of restraint and cooperation and obviously I would never condone inflicting this kind of injury on uke. Some injury, but not too much...