Technical Analysis will give you an edge, but remember it doesn't work 100% of the time. Understand that certain technical set ups are more likely to be successful than other set ups. Wait until the pattern is confirmed; or a break out occurs, before entering your trade. If the pattern fails, you have to be disciplined enough to exit the trade right away. Find the chart patterns that are the strongest and work best for you. Learn the patterns inside and out; and only trade these patterns so you have a better chance of maximizing your gains and minimizing your losses.
Many day traders are never profitable, because they fail to put the necessary amount of time and effort into their trades. Day trading is a tough gig, and you should spend time outside of market hours researching and learning. Before entering a trade, you should thoroughly understand technical analysis, and take the time to scan stock charts for profitable set ups. Establish strict trading rules, and adhere to these rules no matter what. It's very easy to become impulsive and enter trades for no reason other than to trade. Keep detailed records of your trades, and review them each night to help you improve your results. Stay true to your trading rules, and expect to see results that mirror the amount of time you put towards this job.