Before buying your Christmas lights you will need to have the right Extension Cords, timers and power calculations.  Given these we will be able to calculate the total amount of power you can use which may limit the total amount of Christmas Lights you can buy.  

There are a few things to note about safety before you get started with your decorating. Outdoor Cords should be marked with labels that read either UL or ETL. These labels let consumers like me, and you know that the cord has been tested by a group with an independent laboratory, known as Occupational Safety and Health Administration, or the OSHA. The packaging that the cord comes in should also state whether the cord is for indoor or outdoor use. Since we are decorating outdoors, we need an outdoor cord, since these cords are weatherproof and can be used in harsh conditions like ice and snow. Not only are they water proof but the outdoor extension cords are generally thicker due to the insulation and sheathing that is used which makes them more sturdy and able to carry current over longer distances.  Another thing to get for your decorating is automatic timers. These work by turning off your lights during the night and when you aren’t at home.