The best part of dialog... Try and leave actions out of it, have only two people speaking at any time if possible... That way you only need two alternatives for "said", and then the reader can follow along by the way diaog is structured =) It's a cool little tip... Or if there's a niche to the way two people talk, you can have three talking at once... used to use that trick a lot myself.
I usually just use simplistic ones, and stuff like "giggled, slapping him gently on the arm" and such to kind of break the dialog and keep it from droning on.
When I was younger I had an English teacher I used to speak to alot and he and I would discuss my writing a lot.
Well he gave me an exercise of writing a big story, never using the word said.
And although this was a great exercise the word said should be used more than alternatives because other words can draw the attention away and the reader has a break.
People when reading, skip over the word said and so it is a good word to use. They just scan it.
But that doesn't mean you just use it. Putting in the odd alternative is a good idea but never abandon said as it is a very useful tool.
This is very helpful! I know several synonyms for the word 'said', but whenever I'm writing my mind blanks out on me & I can never remember any other words. It's frustrating!