I use Dektol. Mixing it is no different from mixing D-76.

I then divide and store it in many 250cc bottles. Mixed 1:2 makes nice 750cc one shot solution. Stored that way, it lasts at least 6 months. I usually run out before that time, anyway.

Once mixed 1:2 and in a tray, Kodak says to keep 24 hours. But, I have put a saran wrap (not over the rim, but the wrap actually touching the fluid at all surface) and kept it that way for 3 days. The print looked identical to the first. I don't do this for keeper prints but if I'm testing something or just making contact sheet or junk prints, it's a good way to do it.