Put a belt loop on the back, not all trousers have tool tabs. I have even thought mine could do with a leg string at the bottom (like the old gunslinger's holsters) to stop it flapping if you have to run or jog. What kind of jobs do you do where it may involve you running or jogging, unless your working in Syria or Iraq ☺
I use something similar to this Plus can put pens and pencils as I'm forever losing them if I put behind my ear http://m.screwfix.com/p/forge-steel-carpenters-tool-belt/80289