1) Use your existing clientele to your advantage
Start marketing your Christmas light installation business during September. Do not wait for November to start getting orders. If you disregard the notion that time generally runs fast than most people want it to, people do use Christmas lights for many other purposes and not just during the holiday season. A summer party can make use of Christmas lights by wrapping them around trees and bushes. Even a romantic dinner or a family barbeque can have the same decoration. Any party can be made to look more beautiful with Christmas lights, so make sure you tell your existing customer base that you offer this service as well.
2) Ensure you use only top quality commercial stake or clip
One thing you do not want to happen at any cost is to see an angry customer's face because he/she called you for a revisit since the clips you installed broke for whatever reason or for using a power stapler to install the lights. Attachments and clips can be installed permanently, especially on surfaces such as vertical surfaces or stucco. Make sure you talk about these options with your client prior to installation. Commercial stakes do not break often and some varieties are pretty sturdy.
3) Be a lighting designer
One step you absolutely cannot underestimate is showing your customers some sample lighting arrangements. Be the designer. You never know what customers prefer. One of them would like the energy efficient LED lights while the other would like the bright C9 bulbs.