I thought it would be useful for people to post some tips on things they've found useful that others can use.
I can think of 3 from me that I use:
1. If you use hot water, soap and a sink brush you can scrub off the dried paint on a palette without using a scraper. This might take a bit longer but it doesn't scratch the glass as a blade can. I've done it for months without having a scratch on there.
2. If you use 2-4 smaller pieces of glass for your palette instead of 1 large piece then you can clean one of these smaller one and have a new area to do more mixing with if you run out of space, rather than having to clean the whole large glass palette.
3. If you really need to paint to the bottom of a canvas or board and your easel would get in the way of the paint brush you can use several drawing pins lightly pushed into the bottom side of the board / canvas and then reach the very edge without painting on the easel.