Lets face it....
The majority of the guys who are totally against tipping are not against it because it's not customary; it's because they're cheap fuckers.
Personally, I'll tip but I don't go crazy. I'm not trying to impress anybody or win anybody over. Here's how I handle it:
Taxis-depends on the ride. If the guy has a good attitude and maybe even engages me, I like that, so I'll leave the coins. If I get an anti-gringo vibe, he gets shit.
Maids-leave 1K daily minimum; if I make any requests such as extra towels or whatever, I'll leave an extra 1K
Bar-depends completely on the attitude and efficiency of the bartender; if she doesn't greet me, smile, or act friendly, or if I have to wait at the end of bar for 5 minutes as she's talking to her over-tipping gringo, no tip. He'll subsidize me I'm sure.
Restaurants-depends on the service. We all know good service. Assuming the bill is $60, I'll leave an extra 2-3k ($4-6) on top of the 10%.
Girls-I tip
ONLY for good service, not for business fuggs. If you pay $50 at an MP, she gets about $25. If you tip 5k ($10)- my usual tip, that's 40%, but I don't look at percentages. I could care less what the percentage is. I know $10 will make a difference for them in relation to their "salary". I would be too embarrassed to tip 1-2k. And I don't appreciate or give into the demanding of "tips" by chicas. Homey don't play that... NEXT! I have never been forced into a tip. Ok, maybe once, but she has my dick deep in her ass so I was powerless

. And I don't tip at all for mechanical fuggs. If hey ask for a tip, I tell them why I'm not giving them one in hopes that they will see the light.

Doubtful! If they don't ask, I just leave or escort them out and don't say anything; I don't need to rub it in.
Door/security/reception-unless they do something extra to help me in some way, I don't tip doormen, security, or reception people.
Street-I don't give money to beggers. I have bought food on numerous occasions, but I don't give money.
Fast food-I never have nor would I ever tip a fast food employee anywhere.
Skycap/hotel bags-I'll tip only if I requested their services. A couple of months ago, I was leaving India and I had only a carry-on. As I get out of the taxi near the burn, this skycap runs over one of those passengers luggage carts (not the big one they usually use) and grabs my bag. I said no thank you, but he starts to roll towards the entrance. Fine. When he unloaded the bad at the counter he was pretty pissed that he didn't get shit. I told him, "I didn't ask for your help". He mumbled something and left.