You don't have to be desperate to go online dating. I found it suited me at a time when all my friends were either miles away or coupled up. It was a good way of meeting people. Having said that, I didn't half meet some nutjobs. These would be my tips:-
1. Pay for a decent site
2. How you write your profile will determine who you attract. If you write the normal "I am 25 years old, blonde and wltm a caring man for good times and possibly more. Likes, meals in, walks on the beach Dislikes cruelty to animals and children", you will attract the hard of thinking. You need something slightly catchier that stands out.
3. Don't put a pic on there with cleavage or a pout - you will then only attract a certain type of man.
4. Never ever give out too many personal details until you've met someone in a safe public place a few times.
I met Mr BM online. ALthough today I might kill him, so it could be bad. ;)