Great thread with good responses so far.
I've got two at the moment, pretty obvious for the experienced but can make a difference for the newby.
During a removal on a tree (assuming your wearing hooks), If you need a good comfortable work position without sliping whilst limb walking, gaff into any crotch or collar(If there are any) on the branch rather then the bark. Now, no more slipping and tearing up the bark
.
For gear maitenance, buy an air compressor. $100 super cheap auto special. It will cut your maitenance time in half for those of you that clean out your saws with a rag and toothbrush.