I'm going to try to keep this short, but there's a lot I've learned over the last 14 or so years of reloading. The biggest thing first and foremost is safety and paying attention overall. I know this gets preached and is said a lot, but it can't be said enough. You can get as fancy and elaborate as you want with your equipment and components, but one slip up can ruin your day or injure your rifle or worse of all yourself. I don't want to turn this into a boring safety first post, but just double check what powder is on the bench, double check your loads, and if your brass has loose pockets, cracked necks, signs of case head separation, etc. just throw it away.
Now with that that's out way, let's get into the other lessons I've learned. These are in no particular order, just whatever comes to mind first.
-This goes with safety kind of, don't start out at book max or with your buddy's load or an internet load. Always drop down and work up. I like to start 3gr under book max and work up.
-Virgin brass produces different
velocities/pressures than once fired
-Mixed headstamps produce different velocities/pressures
-Get yourself a CBTO bullet comparator and headspace comparator. This makes loading consistent ammo and setting up your dies much easier.
-Don't bump your shoulders back on your brass until fired cases start to close with some resistance. This ensures your case fully forms to the chamber and could take multiple firings before a fired case won't chamber easily.
-Always weigh your charges on a scale, don't throw charges unless it's for plinking and you're using a ball/flake powder.
-Don't settle on a load until you have 100+ rounds down the barrel. A load that's safe in the first 50 rounds can start showing pressure signs as the barrel breaks in.
-We are all guilty of this, but don't go down the rabbit hole of buying better equipment. Your scale only being accurate to 0.1gr isn't the reason your groups are over MOA. Better equipment never hurts, but wait until you outgrow what you have before spending money on new toys and not more components and trigger time. You can just buy the "best" right off the bat, but it's not necessary in most cases.
-When developing loads, don't go about it randomly. Start out with a bullet, powder, brass, primer combo you want to use and test different powder charges and seating depths. If you're not getting the results you want, then change either the bullet or powder but not both at once.
-Don't be afraid to change. Again, I'm guilty of this. If the combination isn't performing consistently or not meeting your expectations, then change the powder or bullet.
-When you find a process and technique that works for you, stick with it until you outgrow it or you're not getting consistent results. I'm guilty of trying new things all the time, but going back to proven methods usually irons things out.
-The "most accurate loads tested" in the manual are with their lot of bullets, powder, brass, barrels etc. It's not always going to work for you.
-Buy premium bullets, powder, and brass when you can get it. Look around at what successful shooters are using and copy them. Experiment after your reach your goals and want to have more fun with it.