BootFrom an expert (Not me:-) though I follow the procedure everytime I put on my boots.
If your boots FIT that's half the battle. Friends don't let friends ski sloppy fitting ski boots.
Pull out on the toung to slide a thinly socked foot into the boot.
Once in, don't wriggle around too much. Stand up and flex forward lifting your heel, then pull up on the back part of the liner to lift the liner heel onto your heel. Step down in the boot, settling both the liner and your heel deep into the heel pocket of the shell.
Start buckling from the top down:
Booster strap goes UNDER the plastic boot snugging the liner to your lower leg.
Buckle # one snug to contact with the liner. i.e. leg, liner, booster,boot. NO Air spaces! No undue compression either.
Buckle #two: the ankle buckle More Snug than buckle # 1
Now with these two top buckles closed, Stand and lean forward in the boot, leveraging your heel into the heel pocket. Pulling the toes back away from the front of the boot. While leveraging, close the bottom two buckles, three then four. These just need to be closed, not tightened. You should just feel the shell closing around your foot like a handshake. Your boots do fit don't they? Let the ball of your feet flex a little. We are not practicing foot binding to make dainty walking after skiing. If these buckles come loose, snow gets in the flaps and makes for cold wet feet, so they need some tension.
Now your in! Give the Booster strap another hard pull to make good contact with you shin. We don't want any shin bang now do we? Go back to buckle # One and grab the next tighter notch. Then to buckle two. This is the "buddy buckle". If you are a racer, You get a buddy to buckle it down ;-) Tight. That's the control buckle. Tighten it.
That's a useful "how to buckle" How much to tighten buckles? I suggest you try different settings ands see what works for you. My "tight" might be your pain threshold.
I know these things from my own experience.
If buckles three and four are too tight, my foot gets cold and looses "feel" associated with it's normal action of spreading etc. when pressured.
If these two buckles are too loose, I get snow in my boot, and the dreaded black toe nail from having my foot slide forward out of the heel pocket and toes jambing into the toe box.(I have one now, but from soccer cleats ;-(
When the going gets tough, steeps and bumps etc. I like to give buckle number three a few turns tighter on the micro adjust or even go an additional notch on the catches ( this does not apply to those who truely "buddy buckle".)
If buckle number one is too tight, my entire foot checks out and I have no "feel" for the skiing. If buckle number one is too loose, I rock back and forth and get wicked shin bang. This is the worst thing in crud and heavy deep and broken snow conditions.
Too much for such a simple thing, but get a routine and it becomes second nature.