Don't be tempted to waste your power-ups early in the game, it is better to save them for the later stages when you really need them. When you do need to use the power-ups make sure there is not a barrage of bullets around them.
Style
Distribute your Upgrade points according to your style of pay so you get the most benefit from them. For example if you like taking risks opt for the extra health while if you are a more cautious player it is more beneficial for you to have more extra shot spread.
