Groom yourself well. Women are attracted to men who take care of themselves. This means keeping your facial hair looking neat and taking regular showers.
Wear clothes that look presentable. You don't have to look formal for casual dates, but having style will make you more attractive. If you are unsure about what clothes to wear, ask a stylish friend to help you out.
Do your best to eliminate bad habits that women might find unattractive. For example, many women are turned off by smoking and excessive drinking. Not only will women be more attracted to you if you get rid of your bad habits, but you will feel better about yourself too.
Decide what your best qualities are and emphasize them. These could be personality traits or physical aspects of yourself that you are especially proud of. For example, if you have brilliant green eyes, wear shirts in colors that complement them and make them pop even more.
Be confident in yourself. People are drawn to confidence. If you are not a naturally confident person, practice acting confident in short interactions with people, such as at the checkout line in the grocery store. Posture is a big part of looking confident, so carry yourself well when you stand and walk, and keep your back straight when you sit.
Be respectful to other people, not just women. For example, hold the door for an elderly person or be courteous to employees at businesses. Not only is being respectful considerate, but it also lets women see that you are a caring person.
Joke around with the girl you like. Playful banter shows her that you are confident in yourself and you aren't worried about what she thinks of you. For example, you could tease her jokingly as a friend would or tell a humorous self-deprecating anecdote.
Listen to what she has to say. Listening skills are valuable assets to have when interacting with anyone, but especially with someone you are trying to attract.