I don't have a tumbler as I have the Hornady Hot Tub Sonic Cleaner, which I recommend. I have done it both ways, but I do wish I had a tumbler because I would throw them in their first before I deprime, neck size, etc. One of the disadvantages of having the hot tub cleaner is because I have to wait on the brass to dry. I have heated brass in the oven 1x to move the process along but I don't think I will do that again. But as for me to answer your question, I would tumble for whatever amount of time to get the brass somewhat clean of dirt and grim before running them through a die. Dies are delicate and should be kept clean just like all the equipment. Then I would run through the press. I would then clean again after that. I do a 10 minute cycle and then let the brass dry, Then I do the press work. After that I do a 30 minute cycle and then a 15 minute cycle. The brass comes out pretty good inside and out. I am new to reloading, but this is what I do. Some reloaders I know tumble for about an hour after range or before starting reload process, do press work and then run a 30 Minute cycle in the Hot tub. Comes out pretty good. I am not too picky about how shiny the brass is. I usually use the Hot Tub for about an hour at the most. Usually 35-40 minutes the brass is pretty good already for me and is reloadable IMO.