Yes, I use a sharpie!  Best marker to use.  What else?

I mark my ball with two lines, easy to identify when you walk up to it.  Saves time and trouble.  Otherwise your partner has to keep looking, sometimes turn it over.  We want it easy to spot from a distance.  Move along.

I had a friend of mine did not believe in marking his ball.  He felt it affected the flight of the ball.  But he was not that good a ball striker.  I mark my ball with something easy to spot from a distance.  Saves time when trying to identify it!

I put a C (First initial of my last name) with a blue sharpie in front of the ball number on each side under Titleist.  I particularly like playing a #4 ball, because, harking back to my days in the army many years ago, it makes me think of hitting an "explosive" shot- C4!

i mark my prov1 with a single black dot below the number

I mark mine with a single red dot above the L in Titleist on both sides.

I always mark with one dot and a pink line for allignment

I'm a junior golfer and I competes nationally, when I play in these events before we show each other what ball we're using. Everyone has a different type of mark. I draw a little vineyard vines whale on mine in blue. Its only so that you can find your ball

I use Rickie Fowler Marks

One black dot to the left of the number.

I use an orange Sharpie and mark through the alignment line. 

if I'm with one person i'll jus mark one dot whatever color sharpie i have in my bag, more then one i'll do two with different 

colors. lately i've been using a single blue dot and tee it up the dot facing my driver's face. it's nice cause after i rip one down the 

fairway. when i look at the face of the driver or fair wood i'll have a n ice lil blue dot in the center of the face. and even on bad shots

it's nice to know where the center of the ball hit off the face of your clubs. but anytime my ball hits the cart path or gets scuffed up 

i'll switch out to a new ball after that hole. putting i like to use a line and of course a fresh ball. i know some people don't care

if there ball is dirty but when putting i like to know my ball is going to roll perfect and not hope around because i got a huge

dirt spots all over. to me i feel it will throw your ball off line when its dirty or scratched. but that's jus me

Two red dots under "Titleist" and and red line along the putting line

I've always marked my ball in a Shamrock, using Green Sharpie, with a centerline Black after spinning the ball for the true line for allignment.  The marks are no distractment and the othefrs always know my ball when they see it.