I thought it would be educational, to see how others score quickly on the fly. I am always wanting to learn and better myself in this great sport. I will tell you how I do it, I'm sure there are better ways.
Take a typical 10 point
I look at g2,g3,g4 quick add let say 8,7,5 =20
Add g1 say 4" = 24
Look at MB if it's straight not abnormally long give it 18"
Long curl in give it 20"
Almost touch in middle 22"
Let say we give this one 20"= 44"
Look at overall mass, this may be hardest for some but if you kinda know the type deer you been taking in the area helps
Let say h-1 is 4"
H-2 is usually close so I say 4"
Drop h3 to 3"
Drop h4 to 2"
Mass 13"+44"= 57"
If pretty symmetrical 57"x2 114"
Add width say 16" = 130"
+ any trash
This isn't as long as it seems, I can do this in about 30 seconds. The size of your deer can change the looks, but if you know your area this can be a quick guide.
Let's see How others do this?

Ive just measured alot of deer in the 120's 130's 140's 150's 160' that just by looking at them for a second I can normally get -+5" in seconds with out adding those numbers in my head. That is the similar way I got started.

I will use a frame score then add in tine length(use one side on all bucks then double it) for quick score. If it is a ranch I know the deer then I will use an average frame-85,90,95 or 100". If the average on bucks taken is 90" then that is what I start with. If the buck is wider or heavier or longer beamed then I might adjust it. Ranch I managed in the Hill Country we used 93" for mature trophy bucks since that was the average over a 3 yr period. The last ranch I managed we had to use 100" since the bucks had better beam length and more mass. I generally just say 90" then add in BT, the G2's and then G3's (G4's and NT's).

The frame yal refer to includes beams spread and mass correct?

Never looked at our frame measurements singled out, gonna have to do that.

Stx like this ?
Frame = MB,mass,spread
+ g1,2,3,4 x2
= rough

Yes.
If I think the buck has 4" G1's and 10" G2's and 7" G4's. I will say 90" then just say 98", 118" and 132" in a matter of seconds. You get a score as fast as you can look and add. If he is close to a shooter then I will take a few seconds longer to look at all the points and mass/spread/beams. It is not perfect but when in a bind it helps.
I also have scored 1000's of sheds and kills off of ranches I was on so that really helps build an average number for frame score. I also have a lot of mounts that I have killed for reference. I can look at a buck and say he looks a lot like this buck and will score what the buck scored.

Look at the deer count the points and my brain somehow calculates the score off frame size/points...

I also might use a different mainframe guess on an 8pt vs a 10pt or 12pt typical. Some ranches a mature 8 point will only be 85-90 on frame where a typical 10 might be 90-95. What I have found on some ranches is that a narrow buck will usually have more mass than a really wide buck. Beam length will be pretty close on narrow vs wider bucks. A lot of the averages you will use will really depend on the location in the state and the management that has been in place.

Thanks Stx, I like learning better , quicker ways. I usually know a shooter when I put my eyes on him, but I want to be pretty close when I pull the trigger.

score as many deer as possible... anything even old ones just laying around no matter how big or small... step back take a guess then score it... more the better.

After years of doing it, I am usually within a few inches with the exception of perhaps some non typicals; however so far on them, I have been on the lighter side, which is always a good surprise after the scores are calculated. Generally where I hunt, the bigger mature WT aren't hanging around long enough to break out the calculator or pencil and paper, so you have to age, rough score and shoot in a relative short period of time. Game cameras have been a big help too in this area WHEN you can get one of your big mature bucks to pose for a picture.

I give them the frame score then just eye ball points. I take into account the area, age, and range conditions before I throw out frame.

For example good mature bucks from say San Marcos area, I'll give 80" frame. Panhandle good mature bucks I'll start with 90"+ frame, just due to body size and history of the 2 different herds.

And this. After a while just one look will get you in the ball park, then work out details.

I always try to score low. My usual guesses are 6" low on bucks and rarely am I over on them. Makes for no ground shrinkage which is much better. If I take my time and score through a spotting scope or binos I can get much closer. Bucks that are the most difficult for me are the larger bodied mature bucks with really heavy mass. I can miss a buck really low with that combo. Mass just hides everything on score.

I go with stx method. Generally start out with about 90 frame inches, adjust from there, and then add tine length in. If you have a history on a certain place or area you can get it nailed down pretty close.

I start with 72" (32" for mass and 40" for main bead lengths) that gets real close on a mature buck here. Then I add tine lengths and inside spread. According to the deer, I may add some for main beams and mass. I'm usually within an inch or two on my bucks. Northern Bucks and I'm lost, body size throws me I guess.

that works OK until a guy shooting 160's walks up to a 180's.

What's wrong with that sounds like a good surprise.

Even though its just trail cam and dead pics that get put on here most without a score ever coming up I still try and look at everyone of the bucks posted on here and put a score to him...

Now when your talking about hunting I could care less... yeah its cool to know how big a deer is or have an idea... but im looking at age before scores are thought about... all my places its 4yr olds and older or bad injured deer... maybe a 3yr old 6 but still not likely... The ones iv guided on were the same.. we let 4yr old tens walk and a handful of 8-9points but didn't have to...

Unless your paying by the inch

I have an ap called trophy score. When I am in the stand or looking at photos I just use it and it adds it up for you and has like 20 different animals