Can I Make my Goatee Grow Thicker?
Probably not. The density of your follicles is genetic. That's why many guys with perfectly healthy testosterone levels can't grow decent facial hair. If you have concerns, see a dermatologist or an endocrinologist.
There are, however, some hair products designed to make your hair seem thicker than it really is. You could try with one of them, to see if it makes any noticeable difference.
Some people claim that more frequent shaving makes your facial hair grow thicker and/or faster. Believe it or not, some legitimate studies have been done on this. Unfortunately, they've shown that extra shaving doesn't make your hair density thicker, but it can make the hairs coarser, and may affect speed of growth. Basically, it may help, but there's no guarantees.
How Should I Trim my Goatee?
The one disadvantage to a goatee is that it's fairly high maintenance. The best way to get it trimmed is by a professional--which you should do once a week if you want to look really sharp. But be careful: some pros are very skilled with goatees and others have no idea what to do with them. In general, you're more likely to find the former kind at an old-style men's barber shop than at a unisex hair salon. Even so, it depends much more on the individual than on the place.
If you must trim your goatee yourself, get one of those magnifying mirrors so that you can see what you're doing. Here are some guidelines for shaping it. First, don't let it extend past the smile lines on your face. Second, if you wear a mustache, keep it well defined above the lip. You may also want to shave the part above the nose, if it looks like there's hair growing out of your nose. Third, make sharp corners where the sides of your goatee meet the horizontal line under your chin, and limit the width of beard under your jawline to an inch and a half. Finally, since your goatee grows in different directions, move the clipper in all directions. The clipper should be set between 3/16ths and 3/8ths of an inch.
Use shampoo and conditioner on your goatee at least as often as you condition your hair--if you want to kiss anybody. You might consider shampoo from www.beardsley.com - the world's only specialist beard shampoo and conditioner.
What if it Turns Grey?Although goatees are often associated with young men, many grey-haired guys now sport distinguished grey goatees. If you can't stand being grey, it's okay to dye it, but again, if you can, have it professionally done. Those off-the-shelf kits can't guarantee what results you will get. Also, some people have said that due to the skin under the goatee being more sensitive, dying can irritate it.
What About the Rest of my Face?
There are a couple of points to mention. First, stubble looks lousy with a goatee, so shave your cheeks twice a day if you have to. Second, you should grow sideburns with your goatee unless you shave your head, but don't grow your sideburns any longer than the bottom of your earlobe.