those are all beautiful!
couple of things you can do. i like to place an old towl underneath to keep it from getting muddy (it absorbs the excess water and dye). you just sort of gently turn and spread the yarn to get under and in the middle. you can also dye by dipping the yarn (i haven't tried that yet :D) you could dip both ends in two different colors or do a fade effect by putting the whole skein in you dye pot (with the dye added) and at intervals slowly pull the yarn out. you'll have to keep the heat on and keep adding h2o and dye as you go. but it's a pretty effect!