Well, you can do the standard breathing in through the nose, hold for a second or two, then breathe out through the mouth, (tongue should be high, the tip against the back of the upper front teeth). Make the in drawn breathe slow and steady, the out going can be a bit faster... in for two seconds, pause for 1-2 seconds, out in one second, or increase these by a second or two each. this helps regulate oxygene to the blood, prevents hyperventalation and introduction of too much adrenalin and helps prevent panic.
For actual impact breathing, you have two methods... the first is to breath out hard and fast when being hit, blocking or striking.... short sharp breath in, sharper and harder out.............OR...........you can breath in as you block/parry/deflect - slow and steady, and exhale sharply as you attack.... this helps the muscles work more efficiently, (along the lines of kia!).
If injured/wounded/winded.....breathe out as much as possible, right from the gut... once you feel like you can't breath out any more, take a short, slow breathe in, then out hard, then breath in for longer.... do thise three or four times, each getting longer and taking in more air.... by the fourth time, you should be breathing normally!
If suffering a stitch in the gut, back or other such place, breathe out while the area is relaxed, then tense it as much as possible whilst not breathing, then loosen the muscle and breath in gently... repeat the process a second time, breathing out more, holding for longer, then breathing in for more air.... if needed, do it a third time as fast as possible! Out hard, tense hard, relax and in hard! This should cause oxygen to reach the location needed, alongside additional blood to help wash away the acid and carbon dioxide build up.
Is that the sort of thing you are after?