I carry a red Sharpie in my bag and mark my balls before each round  I put a simple circle around the number  on both sides of the ball.  This might upset the balance for some pros but with an 18 index I haven't had a problem

I use a purple sharpie, put a dot on both sides of "Titleist" on both sides of the ball. I haven't seen anyone use purple so its easy to spot my ball. 

I write my kids names on each end of the aiming line - one on each side oldest to the left youngest to the right.  Color usually matches my bag color (So currently blue sharpie).

I put my initials on my ball , so it's easy to identify. I play in a lot of tournaments and everyone else is using dots dashes and lines. Play well all.

Generally nothing more than my initials if necessary (usually in red).

I put a big R which stands for Russ or Realtor, which I am. I get some strange looks but that gets me to say that I am a Realtor. I use a Lime Green Sharpie which really stands out.

I mark my ball with a red dot above and below the titleist because guys with one long back line are hiding my Pro V1

I always mark it with 2 green line on each side of the ProV1x and then a green shamrock!!!

I draw a blue circle around the number of the golf ball.

Me too!

Three dots  in the form of  a V around each of the numbers. I usually use a blue Sharpie. I sometimes use  A Tin Cup " Cuban" template.

Mine is similar to Andy's mark. A red dot on either side of the ball number and, a red line on the "seam".

2 orange perpendicular lines next to the velocity alignment line.

Three black dots in a triangle

There are a ton of people who play Titleist at our club, so I always mark my ball.

Use custom number 5 w/ my initials for personalization. Mark with a circle around number and 3 dots across top of Titleist script. 5 represents our family and the dots represent my kids.

Really cool to read how everyone marks their ball!

sharpie; black dot, left of #

I once had my 2 dz.balls imprinted "Lost By Tom" on one side and "If found Please Call" followed by my cell number. I actually got several calls wanting to know if there was an award so I did not do that again. Now I use a sharpie to put a triangle of three "Carolina Blue" dots on each side one under each end of Titleist and one below the number.  

Kind of like Jay H. My golf balls are family dedicated. I have my kids and my father first initial on my golf balls. I also put a black T in between the arrows. Fun to show the kids and they have started their own ball marking tradition.

Since I had a golf ball stolen from me on the course many years ago by some big redneck because I did not have a more on it, I now always mark my golf ball with my initials in green above the logo.

I mark a Mizzou tiger paw by putting four dots over a slightly out-of-round circle, usually in hot pink Sharpie. I also use the Tin Cup Trailblazer paw print to get the same look. I use the Tin Cup breast cancer ribbon, too -- also in pink. 

Red and Blue dot on either side of the Titleist logo to match my teams colours. Crystal Palace FC!

either three red or three blue dots to the right of the ball number in a triangle form.

i always mark my PRO V1 with a Blue line, right over the words and arrow pro v 1 

When I open a new sleeve, I mark one ball with 1 blue dot next to the number, the second ball with 2 blue dots, and the 3rd with 3 blue dots. That way if I need to hit a provisional ball during the round, (happens more often than I'd like, sadly) the balls are marked differently so there's no question which one is in play.

Light Blue Fluer Dies Lis ,, Irish and French Canadian heritage----All American!!!!