I like to decorate cookies, but lately I've been having a great deal of hand cramping. I have a couple questions for the cookie bakers who do dozens and dozens of cookies:

What do you do when your hand is so tired that you can hardly squeeze the pastry bag? Other than taking frequent breaks, I mean, that much is obvious. I've also seen paraffin baths come up in my searches, do they help appreciably?

Has anyone found a difference in exertion between using Toba's glace or royal icing? I greatly prefer the taste and texture of TG, but I sometimes find that in order to obtain a certain control over the icing, I have to thicken it to the point where it gets very tiring to pipe.

I (and my hands) thank you in advance.

I can definately empathize with you. I honestly push my way through as much of the piping that i can and then put everything down to take a break. After about an hour or so, i'm able to come back to it.
To me there is no diff in exertion between the 2 icings. For bordering, i need the icing to be stiff enough to stand (like for shells, stars, ruffles, etc) so either icing works once enough ps is added.
For flooding, i find squeeze bottles more helpful that a decorating bag.
HTH
Oh yeah, i once went to a therapy clinic for my hands and got the parafin wax baths. It didn't help but you could always try.