Most of the tools I have are freebies given by family so don't necessarily suit me (e.g. my spade and fork are probably too big for me) and I have problems with my back so I'm trying to think of what might make life easier.
1st on the list is a stool (like a fishing one!) so I can avoid bending to do tasks that are between ground and standing level.
Was also thinking about one of those forks with a corkscrew type blade that apparently makes weeding quicker than a straight fork. Are they any good??
Anything else you find good for helping you garden for more than half an hour at a time? 
From a technique perspective, I want to start incorporating grit, manure, bark etc, as I have heavy soil, so helping to make it easier to work with on going is also on my list!