The old rule of thumb is to put the round ball in the palm of your hand and cover it with black powder to start with.
Put some white butcher paper on the ground in front of when you shoot and look for unburned black powder.
Add or decrease powder until no unburned it the paper
Here is my list of equipment progression.
Lyman 310 Tong Tool
RCBS Jr Press
Lee 3 Hole Turret Press
Dillon Square Deal
Dillon Upgraded it to a Square Deal B (For Free)
Dillon 650 with case feeder