on standard (wind adj) leupold bases, i start by putting the bases on and screwing them down real tight - no loctite. then i put the front ring on w/ a large crescent wrench, and turn it in until it looks straight. put the rear ring in place, and keeping it roughly centered snug the rear ring screws in - not tight. then i lay the scope in the bottom two ring halves and look to see that the alignment is good. if the scope is laying off to one side, i turn the front ring until the scope is in alignment (note: i use an old tasco scope for this, but as long as you are gentle, your shiny new, expensive, scope can be used).

make sure the reticle is centered in the scope. you can do this by either counting clicks, putting the objective up flat against a mirror and twisting knobs until the two images coincide (2nd favorite method), or unwrapping a new leupold (my preferred method).

now, put the scope in, and make sure it is seated in the bottom rings, put the top rings in place, and tighten down - again, no loctite.

go to the range, and shoot at 25 yards. twist the elevation knob where it needs to be, but do not touch the windage knob... if the windage is off, it is because the scope is not looking down the centerline of the bore. loosen your rear windage adjustment screws, and push the scope in the direction you want the bullet to land (just a little). shoot again, and move the elevation turret, and again, use the windage screws on your rear base to move the windage. once you are on at 25 yards, back off to 100. same routine here: elevation knob for elevation, and windage screws on the base for windage. once you get that on, go to 200, and same routine here.

once you get the windage bases adjusted so that the bullet is dead on left-to-right, and the bullet is striking where you want it to at 200, go ahead and sight in as normal.

if you do not touch the windage knob during your sight in process, your scope will be on l-r for every range (until the wind becomes a factor). if you insist on using the windage knob to adjust, you will note that you can be dead on for windage at 100, but at 200 you are inches off, and by 300, you may be a foot or more off on windage. use the windage knob only for very fine tuning at 250 or more yards.

if you are using weaver-style bases, picatinny rail, leupold dd's, and the like, you are at the mercy of the combined manufacturers in making the sure the scope is centered along the bore axis... just sight your rifle in at 250 yards, and know that you are 'close enough' for anything closer... anything further will take practice time...

nh- don't saddle your gunsmith w/ this kind of work. he doesn't appreciate it because he sure can't charge his going shop rate to do it, and they usually mess w/ the windage knobs just to get you out of their hair...

My method is pretty much like jayrando's with a couple of added features.

Actually,.... I'm really kinda' surprised that no one else has mentioned it,.. but I use a wooden dowel to make sure the rings are in alignment before any scope hits the surface of those rings.

The last thing you want to do to your $300-$500 new scope is bent or dent the tube!  For my real expensive scopes I'll even "hand-lap" the rings inner surfaces with that dowel and emery paper to make sure everything's smooth and evenly matched.

Great topic, and I've learned a thing or two from Dakotasin.

Seeing as how this is an "archive" worthy topic, I'll get right to the point.

#1 Mounting the scope bases
Really don't know if I can add to what dakotasin and 7mm Magnum had to say.  I use a 1 inch wooden dowel to turn in the front scope base as well.  As for whether to use or not use Loctite, I think the jury is still out.  If you go with Loctite, then be sure to use the removable "blue colored" stuff.  Another alternative is clear nail polish.  However, it should be noted that Leupold doesn't say to add any glue of any sort to the threads of its base screws.  If you strictly follow directions of most manufacturers I doubt that you'll need any glue.

#2 Ensuring the scope is level
I'd say that the above comments pretty well cover it all.  Ensure that the rifle itself is level with a small leveling tool.  Once your scope is on, I'd suggest you level the crosshairs as has already been discussed.  There are several scope alignment levels available such as like this one which works by placing the center metal rod flat on the receiver top, then stringing rubber bands through the hooks on the bottom and around the rifle.  Adjust the scope crosshairs to match the black lines and you're set.:

Another alternative is to take a piece of string and pin it to the ceiling of your gun room, attach a weight to the bottom of the string and you have a perfectly plum reference line for your vertical crosshair.  Cheap, easy and flawlessly accurate level every time.  Just ensure that your rifle itself is level as said before.  You can find these levels at several stores and there's different models available.  A search at Brownell's.com yielded these tools.

http://www.brownells.com/aspx/NS/Home/default.aspx - http://www.brownells.com/aspx/NS/Home/default.aspx

#3 Boresighting
Again, the guys have it pretty well covered.  I will add that I don't use a bore sight laser and I always use perfectly round bullseye targets.  The key thing is to keep your sight picture perfect as you look down the bore of the rifle.  Keep the walls of the bore centered, the field of view centered and the target centered.  From there on, do as dakotasin said to adjust your scope "on target."

This is the site picture you should be trying for down your barrel:

(once I can edit pictures in, I'll add these.  At the moment, we can't upload pictures unless they're on the web and my picture hosting site is down so I'll put them up as soon as it's available.)

I DO use a laser,... however it is not your typical setup for a bore alignment tool.

Seeing all of my rifles are bolt action I take a regular "laser-pointer and shine it down the bore from the receivers end with the bolt extracted.

You will know when it is centered just right by the way the pointer shines out the muzzel end and on a wall. I usually do this in our riding arena here on the farm, Its a good 100 ft. long.

If the laser is NOT centered correctly there will be a halo effect either to one side or the other of the smaller red dot. When it IS centered correctly there will be a perfect circle. When you have got that,.. all you do is adjust your cross-hairs to the red dot and your on the money!!

It works for me every time I have done it and the laser-pointer cost me just $5.00.