Hmm I'm not sure if these are all easy, but here's a list I think is easy to add.
-Smile
-Enjoy yourself, your company and your environment (major game booster)
-Update your wardrobe (costs some money, but it's an easy and great improvement)
-Hit the gym or atleast workout at home. Working out itself boosts your confidence even without direct results.
-Fix your posture, stand straight and feel free to tilt your chin up or stick out your chest once in a while.
-Wear something 'cool' or extraordinary, but don't overdo it. Like wear some bracelets (guys rarely do) or a nice necklace girls can open/compliment you on.
-State your questions differently. Instead of 'where are you from?' say 'I bet you're from X'. it'll give alot more to talk about.
-Have values and standards, don't get fooled with or used. (buying drinks for random girls for example)
-Take a breath mint
