I got bored and made a mediocre homemade custom hitsound tutorial. As far as I know there isn't one out there, at least in video form. If there is hopefully mine is better!
http://youtu.be/gPDOwl7jUIw
Website and Programs used:
Download video website: http://keep-tube.com/
*I usually just use OBS or Fraps to local record the part of the video I want. You can skip this step if you want to do it that way.
Freemake video converter: http://www.freemake.com/free_video_converter/
Audacity: http://audacity.sourceforge.net/
My Dingaling Settings:
tf_dingalingaling "1"
tf_dingaling_pitchmaxdmg "40"
tf_dingaling_pitchmindmg "133"
tf_dingaling_volume "0.75"
*You can just adjust the volume of the hitsound this way but upping the decibels in Audacity works fine for me. Audio quality will be better but completely unnoticeable in game.