I Know of a meditation you can do before hand that can focus your mind on your target. Its not really magick but it is a good trick for mental focus. I know this meditation as the grey mask meditation.
make a mental image of a grey mask. (The mask can look like anything)
Now every for at least a week spend 30 minutes meditating on that mask. Fill it with all your hatred. for instance View it on your worst enemy, Just put all your hate towards the mask. After the first week you may need to occasionaly repeat this meditation. You have to hate this mask. make It the source of all harm to you. Then when a fight comes visualize that mask on the person your fighting. if done improperly this can bring on a berzerk like state. If done with enough mental focus it can increase strenght and focus on your adversary. Beware This meditation may make you do things you later wish you hadnt. On a side note this is a wonderful way to remove your hatred of someone since it all goes to the mask.
I have a few theories about how magic might be used for combat, though I've never tested any of these myself. However, anything flashy like you see in movies is woefully impractical at best. Magic takes energy to use, trying to throw a fireball would most likely fail and leave yourself too exhausted to fight. The advantages magic could potentially give in a fight is that it enables you to attack from an angle your opponent isn't prepared for.
Mental magic could be used to influence or obstruct your opponent's thoughts or concentration, but it is just as likely that the focus they place on the fight would leave them vulnerable as protect them, there is no way to know. Something more likely to work is magic that can effect probability, such as protection spells. These could be cast prior to a fight and left on during combat, though I cannot be sure what amount of energy this would take.
Of course, the largest downside of using magic in combat is the amount of concentration needed to cast spells. Passive enchantments, such as protective charms, might be an exception. Casting spells while fighting risks losing concentration on the physical fight. Also, the more effort you put into each spell the less energy you have.
I would only recommend trying these during martial arts sparring against an opponent you have fought before who doesn't know you practice magic. Keep track of any differences you notice between this fight and the last.
I got a couple ways on using combat magic but most of it is sensing your opponets energy and brutally cripple your opponet.
For sensing your opponets every movement make a sphere around you at arm length and make that sphere sensetive to energy. It will take some time to be able to do that since i am still trying to perfect it. Train yourself to have good reactions with that sphere until it comes naturally that you don't even notice that your using it. To some Martial artist it is called Seisuken which is one of the best defensive and offensive techniques known so far. When truely mastered you won't get hit by anyone unless your opponet uses a even stronger technique which then you have to make Seisuken evlove to something else.