Be honest in your ad - if you're just looking for sex then say so. Don't lie about your age, weight or hair colour since most people have a very good idea what they are looking for and you're wasting their time as well as yours. If they are looking for someone older, generally they want them to look their age.
 

Use language which fits what your looking for - if you're looking for a relationship put the accent on the positive things you like to do rather than just your sexual interests. Tell guys what you do like, rather than what you don't. "Looking for masculine guy with slender to athletic build" comes off so much better than "no fats or femmes."
 

The bigger the personals database the more chance you have of meeting someone compatible. But this also depends on the type of people/relationship you are looking for. For instance general dating sites (e.g. Match.com, Yahoo) are geared more to relationships. Others such as Gay.com are offer a more sexually explicit service.
 

When giving out your location try to limit yourself to a region only, rather than the exact name of the town, province or neighbourhood. If you live in a large city, giving that information out is okay, if you're in a rural area, it's better to stick with regional information.
 

Don't respond to immediate requests for money or support - if the relationship is unbalanced at the start it is likely to be unbalanced throughout - and there are plenty more to choose from.  Don't publish explicit photos on the Internet or email them to others if you are at all concerned about others seeing them - you have absolutely no control over their destination once they are posted.
 

Don't send explicit photos that include your face to anyone unless you know them really, really well-probably after a face-to-face meeting
 

Use a different email address for personal ads and redirect the mail to your usual email address (Yahoo mail and Hotmail both allow this)
 

Use more than one personal ad if you want to be explicit or consider password protecting the explicit section of your ad (some personals sites allow this e.g. Gay.com).
 

Update your ad on a regular basis even if it just changing a comma. This should improve your search ranking.
 

Adding a photo as will increase your reasons up to 25% but make sure that it is current and one that shows your best features! Be honest and post a current photo even if you've gained a few pounds.

Smile unless you're trying to look assertive.
 

Take the photo it in daylight but not midday or in very well lit interiors but take care with items in the background.
 

Avoid shadows on the face
 

Take a number of head and shoulders and full-length shots
If you don't have a digital camera or a scanner, use a good ordinary camera and ask your photo lab to create digital images
 

Don't use Web Cam photos since the resolution is almost always too low and the light can make you look like an axe murderer!