The first thing I do is decide what bullet I want to try. I then pick a powder and a primer. I usually start at minimum charge and work my way up to maximum carefully, looking for signs of excess pressure. All with the same bullet, powder and primer. Cases are all FL resized and trimmed. Primer pockets cleaned. I usually start with bullet seating about .020 off lands, if it will fit into magazine. If you are lucky enough to get a good group or two with your first combination, I load it up again to see if it will repeat itself. Document all you have done. On your targets, it's a good idea to write the load combination, date, yardage, weather and air temp. If you don't get any groupings that are satisfactory to you, I would change powders and start again with the same bullet. If you run the gamut of powders and can't get it to shoot, you probably should try a different bullet, and start the procedure all over again. I've had to do this often. Once I get a good, REPEATABLE load worked up, I then try it at different temperatures over the course of time to see if it will still shoot the same. Loads worked up in the summer may not shoot the same in November or December, and may need a bit of tinkering. This is basically how I go about it. I'm sure others on here will be glad to give you their procedures too,and perhaps some of the more technical aspects that I didn't mention and the reasons why. Just MY way........