I started with fingers (still shoot "sticks with fingers) and eventually graduated to the "string loop. In addition to all the positives that have been said, using the loop conserves the serving and eliminates much of the string "twang" that some mechanical releases cause.

Make sure you tie it on correctly and securely. Do not loop the string when you install it. Tie it flat against the serving; ends above and below you nocking area. After installation, slip a small screwdriver under the string and stretch the loop until you can get your release connected. Shoot a few strings and the loop will settled in.