OK, so this is a professional opinion. First, I never tip, unless for cover, if I am losing. I rarely tip during the session but only at coloring up and then do so "appropriate" to the win.
If you are a recreational player then here is a tip on tipping that you should find useful.
Let's say you want to tip a dollar in addition to your $10 bet so you put a $1 in front of your bet. What you have just done is give the $1 to either the casino if you lose or the dealer if you win.
So, now let's do it another way. Same situation only this time I put the tip $1 on top of my $10 bet. Now I retain control of my dollar. If I lose I gained nothing and the casino takes my money. If I win, however, I give a $1 to the dealer and keep my original dollar. The dealer still gets a tip and my tipping cost is cut in half.
BTW, tipping a $1 on a $10 bet is giving an ADDITIONAL 10% advantage to the house/dealer. Even doing this on a $25 bet is an additional 4%. The casino had less of a 1% advantage if you are playing basic strategy before you helped with tipping.
You cannot win very long at this level.
Now, I am a very generous tipper in other where the people have more control over what they can do to provide service. Not so much at casinos. Dealers have very narrow protocols to follow and tipping them to "help" me could be confused as collusion and we could both become inmates. Not ever doing anything illegal.