Yep, that and making sure the lamp has full voltage across it. Halogen lamps need to run at full power for the longest life. With as little as a 10% voltage drop, the bulb lifetime falls off. This type of lamp relies on a reaction of the hot halogen gas redepositing the tungsten boiling off the filament back onto the filament. This reaction is temperature sensitive and at reduced voltage the temperature falls and the reaction stops. When this happens, the filament thins with use and you also get the dark metal deposits on the inside of the quartz envelope, further reducing the light output.