I have used the founder institute recommendations in the past. Some people feel that it's not enough and some even seemed offended but most people that understand tech startups and that have advised or invested in them before should find them fair.

When you think about what most startups offer their full time employees, 0.2% - 1% by the 10th employee or so. 1% for a few hours a month is reasonable.

Also think about if you raise money, how much would that 1% be worth at the valuation you're thinking about? How much would it worth if you exit at your target exit value? Using $ figures I addition to the % helps the advisor get a better picture of what their getting for their time.

Protect your equity, once you give it out you can't get it back ( barring vesting of course ). It's limited and you're going to need it. Not saying you be greedy about it, just think very carefully how you use it.