Note: To use this trick you need to have a your skill cap at full.
If you are using the sword skill, get a mace and kryss and find a
training dummy. Next put all your skills in the lock position and
put your macing up and fencing down. Then, just beat the dummy with
your mace until you get 20 skill on it, then switch to have fencing
up and macing down. Beat the dummy again until you get fencing up to
20. Keep switching and repeat. In five days you should 100 STR and
100 DEX.