I lost my good old pair of scissor I used to cut perfect nice ends to my string. I found that nail clippers work just as well. Give it a shot, I find they work great!
slightly off topic. the best tool i found for cutting string is those cutters designed for plastic modeling. esp the Tamiya side cutters. they are ridiculously sharp and makes a very clean cut. they costs up to $25 so they are not cheap. but well worth it. you can buy cheaper version in Asia, esp in HK but hard to find one that is below $10-12 even then.