how to create guitar loops

Can anyone explain to me a way to make very basic guitar loops that sound good without a noticeable break at the beginning and end of the track…Im not looking for perfection here just something to practice over..I havent been able to do it without it sounded bad when the chord progression repeats…Im just looking to make a few very short loops maybe 8-16 measures so possibly a 30-45 second loop at most. I know if I search all the forums and the manual Ill probably find the information but I`m not looking for rocket science here…just something better then looping the chord progression and having to listen to space at the beginning and end.
Thanks

Viewing the recording as a spectrogram, rather than a waveform, makes the looping points more obvious …

The “Timeline Quick Play” feature (http://manual.audacityteam.org/man/timeline.html#tqp) is useful for locating loop positions.
Note that exporting in MP3 format will add a little silence at the start/end of the file, so MP3 is not a good format for looping files. WAV, Flac and Ogg formats don’t have this problem.