In our experience, we generally recommend tip soldering temperature around 330-350 degrees Celsius or using a soldering iron in the region of 25-35W. You should definitely try to avoid using high-powered irons that come in at 100W or above, for the reason being that 100W soldering irons do not control the tip temperature; therefore, if you don't have enough experience you may end up destroying the LED strip's pcb, due to high temperature.
We therefore suggest that you should always begin at the lowest temperature possible. Start off by setting the soldering iron's tip temperature at 260°C (500°F) and gradually increase the temperature as needed, in order to obtain the desired result.
Additional note: If you are soldering a wire to your contact points, it's always best to solder from beneath the wire, rather than have your soldering iron touching the metal from above. Soldering from under the wire's contact point will allow it to sink in better and provide a stable connection.