Well, if you haven't purchase a press, then you should look for one that 'floats' the dies during operation. That pretty much leaves you to Wilson dies or Forster Presses. It is easier to get concentric ammunition with these approaches.
Around here, most people have had excellent outcomes with Hodgdon 4350 behind 120 grain bullets, and Hodgdon 4831 Short Cut behind 140 grain bullets. These have become the 'go-to' combinations for all the folks I shoot with.
For Bullets, get the Amax or new polymer tipped Sierra. The old, hollow point designs get so damaged in transit that flyers are inevitable. Use only polymer tipped bullets!
Don't load to max intensity. The 6.5mm bullets will carry through to 1200 yards on moderate loads. Their ballistic coefficient saves the day, even when starting velocity is on the low side. The nice thing about the powders I've suggested is it will quickly become apparent where the sweet spots are in load density. We've always found lower intensity loads to work best.
As was mentioned above, get the Hornady comparator tools for measuring the throat on your rifle(s). Seat bullets accordingly. Start with bullets .015 to .005 off the lands.
Milder primers are preferred. I use pistol primers.
Once you've done those things you can play around with weighing bullets, measuring volume of cases, indexing cartridges to chamber, etc. All those things are a waste of time in my experience.