How much do you actually use symbols when treating others or yourself? Many people do experiment them and use them more when they first get them at Level II, but I find that many people fall away from using them and I'm told by others you really don't need to after awhile (?).
I am asking my FB Reiki page group to join me in doing an experiment with the symbols. If you'd like to get in on the fun, try working extensively with them and report back your findings. Like when your self-treating, intuit which symbol you should put in in each hand position and see what happens. The next time you do your self-treating session, change it up and use different ones (make some notes afterwords about which ones you used so you know for next time).
When you're doing sessions on others do the same - intuit which symbol should go in each hand position and see what happens (ask their permission first of course). If you are not intuitive, just pick one at random and when you work on that person again, change it up ( again probably good to keep some notes about which ones you used where then).
If you are Karuna this probably doesn't apply because we use the Karuna symbols extensively when doing Karuna.