When looking around at the avatars in the SL universe, I like to categorize people based solely on their appearance into: The beautiful people (...sheepishly puts down mirror), the newbies, and the seriously Jacked UP! The first two are fairly self-explanatory, so I want to use this opportunity to address the latter. I'd like to say "you know who you are" but unfortunately that is the main problem, you really don't. Your avies are all jacked up because you think it looks good but bruddah you couldn't be farther from the truth. Buying a skin and slapping it on your "masculine" shape then topping it with some prim hair should be as simple as 1-2-3.
1. SHAPE. "Sometimes to build up, you have to tear down." Don't know who said it but they couldn't be more right. If the "base" of your avatar isn't right, nothing else is going to be right. There are some fundamental mistakes that most people make when setting up the shape of their avatar. Unless you are a professional basketball player and want to make your avy and accurate representation of your real body, there is absolutely no reason to be towering over seven feet tall. Now, I will admit, the majority of poseballs and interactive objects in SL seem to be preset for the tall avatars. That being said, most all of them are adjustable and your day-to-day appearance is more important than how you line up on that fancy sexgen bed.
The next issue is what I call "slider envy" where every slider in the appearance menu is at the extreme position one way or another. Max muscles, zero body fat, max shoulder width, zero love handles, etc. Guys, this is not the freaking World Wrestling Federation and you don't have a Texas belt strap cage match coming up on SUNday, SUNday, SUNDAY! I'm not saying your avy shape has to be a true and accurate representation of what you look like behind the keyboard, but I am TIRED of seeing the non-green Incredible Hulk clones running all over the place. This doesn't mean you can't have a sexy, fit, athletic or even muscular avy - you can and a great many ladies will enjoy running their virtual fingers over it. Just tone it down some fellas, trying to be the biggest dog on the block is impossible because there are thousands of 'roid raging robots out there already.
One of the most important features of your avy, and also the most difficult to tweak correctly, is the head and face area. First of all, do not be afraid to make your head larger, especially if you are going for a more muscular build. Keeping the proportions right for your whole avy is important but sadly the head tends to get left by the wayside.... figuratively of course. Making adjustments to your facial features is a slow, tedious, and aggravating process. My advice, pay someone to do it. There are plenty of shape stores and vendors out there, contact the owner and ask if they do custom work. Most will, and will help with other areas you are having problems with for a reasonable fee.
2. SKIN. "Never judge a book by its cover".... ahh, what a wonderful sentiment. Wouldn't it be great if everyone based their opinions solely on the inner strength and beauty found in all of us? Yeeeeaaaah, that'd be swell. Problem is, doesn't work that way. Men judge women by sight from distances that eagles are still squinting at with a clinical "Do her; do her; do her; won't do her; do her...." Hell, men judge women from these distances before they're even sure it's really a woman, "Man, you see the ass on that long haired blonde..... chick?" Guys, don't fool yourselves, women do the same thing, but they usually wait til they are in range to see how dreamy your eyes are. They say women have decided within the first five minutes whether or not they're going to have sex with you. Get a smoking hot skin wrapped around that avy and those minutes disappear faster than she can giggle "OMG! I'm not wearing any panties tonight, teeheehee."
My philosophy is any skin is better than newbie skin. Find something with a skin tone you like, facial hair if desired, wear it and then save your lindens to upgrade to a premium skin. When you are finally ready to take the plunge and get that perfect look for your avy, try not to post in chat "Are they out of their f-ing mind?!?" Great skins cost a great deal, but most come in bundles or "fatpacks" that give you multiple options with facial hair, scalp hair or bald, and even some prim attachments for head covering or a lower unit (flaccid) to complete your nudist look. While women seem to have a penchant for changing their skin from week to week, it's really not expected, or necessary, for men to do the same. Nothing wrong with changing your look if you like, but getting more than maybe an additional good goth/vamp skin or other specialty skin is about all you need. One additional note, you may need to adjust your shape after you put a new skin on. Skins look different on different shapes due to the shading or textures used to make the skin, so take the time to check it out and make a few adjustments if needed.
3. HAIR. "Rapunzel, Rapunzel, let down your..." okay, okay, so I couldn't think of an appropriate quote for this section, sue me! Prim hair, flexi hair, super flex hair, whatever you want to call it. It ALL looks better than that colored mop you start with and are supposed to shape into some kind of head covering. I was going to post some pics of my newbie look, but I deleted all those and burned them. Yes, I printed them so I could burn them as part of a ceremonial cleansing ritual. You must eliminate any visible evidence of that horrible mane by first wearing the "bald head" that comes with every prim hair you purchase. It it not necessary to edit your hair to make it as short as possible, the bald cap will take care of that.
Prim hair styles are seemingly endless in SL. Granted, about 90% are made for women, even those bullshit "unisex" ones, so finding good hair for men is a challenge, but not impossible. Choose whatever style strikes your fancy, don't worry, after you get that girlfriend she'll decide what looks best on you. Just remember to edit your hair after you put it on, especially if you edit your head size as mentioned above. Most hair comes sized for the standard beginning head shape, so you will need to stretch it in edit mode as well as position it correctly on your noggin. One last note about hair styles, and this is just a personal preference. ENOUGH with the long flowing guido mafioso ponytail! I don't know why that one bothers me so much but if I had some prim cutting scissors....
Regardless of how you set up your avy, pick a style, have a plan, and stick with it. Once you get your "look" established you can mix it up, have some fun with it. The best time to change it up is when you are going to a club for some theme night, then you can take a chance with a different skin, different hair, etc. Most importantly, make your avy pleasing to your own eye, you are the one that has to look at it the most. The more you like the look of it, the more confident you'll be and that's what is even more appealing to the female eye. Be unique, make that look yours, and make it work!