Here's what works for me providing my rifle is already sighted in and barrel broken in. I usually take 3 rounds loaded to a starting point with powder, primer and bullet of choosing, then bump that powder charge up in .5gr increments. Somewhere between min. and max loads there will be a sweet spot where your groups will come together. Usually if my rifle is already sighted in I'll start at 100 yards. Targets, I like to make my own on a large piece of cardboard from an appliance box. I draw a red 1 inch dot about 5 inches apart vertical and horizontal on the cardboard, big target will tell ya if your new load is off or on the cardboard. Always start with a clean barrel, and will fire one round to foul the barrel then proceed to fire 3 round groups. After 3 rounds I clean to get some burnt powder out, then let the barrel cool right down. ( This is a good time to find out what other guys at the range are doing, shooting, hunting, politics, ect ..)
When I get home I do a cleaning with a 50/50 mix of Butches Bore Shine and Montana X-Treme Copper Killer using a Tipton cleaning rod until the patches stop coming out with blue on them. One wet patch and one dry patch and repeat. Then a few dry patches and a couple of Ballistol oil patches to finish.
Since I would be shooting at 100 yards wind speed under 10 miles per hour doesn't really effect your accuracy that much. Hot and cold temp. does effect your velocity some but with some newer powders it's not to much unless your trying to shoot in 95 degree weather then again in 0 degree weather. Hotter weather will make the pressure in your cartridge and rifle go up so you want to be careful when working with max. loads when it hot. Hope this helped some.