I do not know why people do not mark their balls.  I saw a marker in the bag of a friend of mine as I was looking for a tee.  I joked "that he must be good to mark his ball".  I made a line thru the "Titleist" just a a lark.  We tee off and there in the fairway were 3 Titleists...all #2.  As we approached and realized that we all played the same ball with the same #, I realized I had marked mine, making finding mine easy.  That was 15 years ago.  Still playing Titelist and still marking my ball with a green line thru the name, front and back.

I place a blue mark with a sharpie on each end of alignment arrow . 

I normally put a "t" on my ball 1 side of the t is for aiming the other for putter face alignment.

5 black dots in the shape of a large star on two sides of the ball.

Single black line about 1/4" under the number. Been doing that for 30 years.

Purple dot over the "T"

Been marking mine the same way for several years . . . One red dot to the left of the number and one black dot to the right of the number on my ProV1x - GO DAWGS!!!

Green dot on both sides of the number. 

Black sharpie, S on the side

I use a shrpie to put a blue dot between the name and the number. Usually mark the dozen at one time so they have time to dry.

Custom imprint with my initials JG repeated as many time as is allowed.  Works great as a line for aiming.

First ball has a large dot above the Titleist logo and if I have to play a provisional, the dot is below the number on the second ball.  Usually black, but sometimes red dots.  And I put one of those alignment lines extending from the Pro V1X line.

I underline the words Titleist and Pro V1 with Neon Orange Sharpie

Just like the way it looks and it says to me, this is my ball, this is my game.

Own it! enjoy it!

Since I'm retiring to Myrtle Beach, SC, in less than a year, and pine for the place uncontrollably every time vacation draws near, I mark my ball with a hand-drawn "Palmetto Palm Crescent Moon Combo" that you see on the State flag. It's big enough that I'll know it's my ball when I see it.

I have personalized Pro V1x with the word 'Astrodude', because I am an Amateur Astronomer.  I then put 7 black dots, opposite of the arrows in the configuration of the constellation Pleiades (the seven sisters), which happens to be my wife's favorite constellation.

I dont like to mark my ball, I don't want anything on them except the titleist logo!!

One black dot to the right side of number