I used to go solo all the time and pull groups of females out of clubs and go to the next spot and eventually back to the crib.
Make sure you have an outfit that can move to any venue and you get in meaning something that looks good in a club concert or house party.
Make sure your car is clean and smelling good, keep some mints or gum in there. Change of clothes and toothbrush in the trunk.
Have cash! This helps if you want to get into a crowded venue. Slip the head bouncer a 20 or more never more than 50$ depending on venue and he will let you in. Also makes getting drinks at a bar quicker.
When you are at the bar chat up those around you. Introduce yourself ask them if they are enjoying themselves, pretend you are the promoter of the place it will broadcast confidence.
Don't drink too much!
Don't plan on staying in one spot the entire night you should hit at least 2.
Next time get a hotel in DC this way you don't have to bring randoms back to your crib and don't have to go to theirs.
Btw one trick I had to loosen me up would be to start my night at the stripclub. I would get me drinks and flirt with the females there, by the time I saw fully dressed women at the club the bar was lowered and my confidence was high.
Enjoy and don't be thirsty.