Until recently my 35mm darkroom was in a shared bathroom and I had to bottle all the chemistry up once I was done. But now that I have a more permanent setup in the basement, I sometimes feel too lazy to pour everything back into the bottles after every session. I know that I don't have much choice with the developer and fixer too will go bad if left exposed over a long time. Even with stop bath, evaporation remains a problem.
So I am wondering if anyone has any practical tips or tricks to keep chemistry relatively fresh in trays. One interesting idea I found was to float another tray of the same size on the chemistry. I must try that, but before I buy new trays, any opinions on that or other ideas?