Decorative outdoor string lights are a wonderful way to add definition and illumination to your patio. You can string lights outdoor in a variety of ways depending upon what sort of look you are trying to achieve on your deck. They are available in a huge variety of styles and colors. You can string these outdoor lights from your railing or from your patio umbrella or even from your outdoor plants. The looks that you can achieve can be quite amazing and spectacular. If you pay attention to detail you can end up with a look that is truly inspiring. You are able to find creative string lighting options in either residential or commercial grades.
Tie One On
If you decide to purchase commercial outdoor string lights for your home you can be assured that they are of superior quality and are designed to last. Commercial grade outdoor string lights usually consist of a harder coating that makes them more substantial. They resist bumps and scrapes as they are originally designed to be used in commercial applications where constant wear and tear is a factor. A great way to add them to your patio is to tie them on with color coordinated plastic strips that make them hardly 
noticeable. If you are lucky enough to be able to find ties that match your deck railing then you are in luck. Otherwise you can attach your string lights to your railing and then use your existing paint color to hide the ties. Simply use leftover paint from when you installed your railing or purchase a small can of spray paint to coat the ties. This way the ties are not noticeable on your railing but your lights are. When you string lights outdoor you want the lights to be the center of attention and not the ties that hold them in place. You will never regret installing commercial grade lighting as the durability is worth the extra price you initially pay.
Budget Friendly Alternative
If you can not afford the cash outlay for commercial grade lighting then you can always opt for residential grade string lights instead. They are less expensive and still give you a great effect. The light that emanates from them is just as strong but sometimes the bulbs do not last quite as long. You can use them just like their more durable counterparts. You can 
wrap them around your hand railing. You can mount them underneath your hand railing if the railing is wide enough. They look great if you attach them along the outer perimeter of your patio all along the floor. If you have a patio umbrella with lanterns hanging from it you can add string lights to your lanterns for an even brighter effect. The choice is completely up to you.
Adding string lights to your outdoor space adds a finishing touch to bring the entire look of your patio together. Your deck ends up looking like it is well coordinated because each area is decked out with pretty string lights.