Well I think you really have to decide how real you want your scenes to be. From what I have read you seem to want realistic and I can give some insight and tips into that, at least as far as fist fighting goes.
Some back ground, I have 21 years of martial arts experiance, starting with karate then into wrestling and then into jiu jitsu. I also have about 7 years experiance working as a doorman in various bars and because of that I have been in more fights than I care to talk about.
Now if you want to write kung fu movie fights go for it, but if you want to write real fights here are some things to keep in mind and maybe try to work into your books.
Fights simply never go the way you planned. You are not spending time planning out moves, most the time your thinking OH CRAP!! and just doing something, thats the differnce between someone that is trained and someone that is not. Its not a magical battle plan its that when your brain is stuck your body will do what youve trained it to do.
The person that hits first most the time also hits last. Sorry but your not coming back from a solid head butt to the nose or getting bashed across the head with a bat. Most fights end in a few seconds, its just how it goes.
Fights almost always end up in grappling, the less experiance people have the quicker they will end up tied up with each other. Also if you know what your doing and the other guy doesnt, grappling is great, you can accidently get knocked out, you arent going to accidently get placed in an arm bar.
People rarely end up in an impromt kick boxing match or karate fight, it just doesnt happen a lot in the real world.
There is no cheating in a street fight, it doesnt matter who does what only who wins. Anyone that is worried about fighting fair shouldnt be fighting at all. Always hit first, always!
Think of MMA, its not as flashy as karate but the stuff works and thats why you see it in the UFC.
You dont see the worlds best fighters doing half the stuff you read about in your average book or see on tv, its a few strikes or grappling. The reason is, in a real fight, fancy stuff aint gona fly most the time. It might seem fun in the dojo but all those wrist locks aren't going to get you half the results of a good double underhook or double leg. Or even a solid head butt or punch to the chin.
Also, when someone is fighting back with a decent amount of skill, half that stuff isnt going to work like you think it will, its just not going to go down like it does in the dojo when the other person is making every effort to not let you do it. This is just something I have learned over the years and through many very real fights.
Keep it simple, the move with the least room for error is your best bet. Think of Chael Sonnens last fight with Anderson Silva, Sonnen was doing great, had him up on the cage, tried a spinning elbow, tripped and got TKO'd. Most people dont have half the skill Sonnen does, and he still flubbed up a spinning elbow and that was that. One mistake is all it takes and your done, thats just the truth of it, no matter how good you are, you slip up your gona get hurt. No one can be perfect all the time, everyone will mess up, so keep it simple!
Defense is generaly not fancy, blocks more often than not mean taking the hit on your arm as your arm is protecting your head or face, you still get hit. Movement is a big part of defense, dont be where the other guys fist is. If you plan on fancy pants blocks and moves you are going to have a ruff time of things. Again, this is just what I've learned over the years, take it for whats its worth. Also the best defense is to never let the other guy have a chance.
Now I'm not saying don't have fancy martial arts moves, but be honest about your characters ability, size, training, and the ability of the attackers. Talk to people you know that have been in real fights, not fake, not practice, not sparing in the dojo, but real honest to god someone trying to smash your teeth in fights. Its not the same, its not even close.
If you plan want to have realistic scenes you need to keep a lot of this in mind, I read a lot of scenes in books and think "ya thats cool, wouldnt work out that way but hey its just fiction".
I hope these little tid bits help. If people disagree well cool what ever, all of this info I earned the hard way lol, its my take on modern fist fights in a real world setting.
