Basically you make your intial print. Then you take the filter that is hopefully near what you need. You flick the filter in front of the print looking for the one that gives the best result. Don't leave the filter in front of the print for long periods of time or your eye will adjust. You then look at the filter you picked and adjust your enlarger filters by the set amount. Make a new print then recheck with the filters. Repeat.

I know some people swear by the filters but I never got the hang of things. I just used my bare eye and adjusted. Also after awhile I came up with a set of enlarger settings. If you stick to a small number of films then you can get pretty close with the intial print using the same settings. Assuming you made a good negative to begin with.

I like drum processing. With very little equipment it's possible to have total temperture control. The main thing you want is something that's repeatable.