If you're using solder paste, apply a small amount of paste instead. Most solder pastes contain flux.

This can be very tricky depending on the size of your component! Take your time and don't press against the component too hard, or you may fling it out of place.

Double-check the component orientation if it's electrically directional (such as LEDs and diodes). These components normally have a bar indicating the cathode (-) end.