Thomas & Betts makes a tool to tighten the ties and it is adjustable for different tensions, I have had mine for about 15 years, I don't know if they are still made, I think I paid about $25.00 .
Thomas and Betts make a version of a Ty Rap tensioner and flush trimmer ERG50. Great tool. Use it daily. Cinches as tight as the brand of cable tie will allow then cuts flush. no sharp edges.... But I think they are 150 - 200$ T&B makes all type of cable ties. Some sunlight resistant (black). The white or tan are nylon, sorta all purpose. I had the company order some that were high heat rated. They are a translucent greenish yellow pkg. Almost a clear chartruese color, good for a few a runs on a nitro boat.