Sometimes it seems just too crass to even think about mentioning money.
This is not the client who calls up saying “I know it will take you only 5 minutes”, selfishly overlooking the fact that you spent 50 hours learning how to do it.
This is the colleague who drives you to lunch each time you meet, the one you phone to cry on a shoulder.
Here’s What You do
I’ll take a spreadsheet as an example; you can change the scenery.
Griselda wants to know how to set up her spreadsheet; you like Griselda and she likes you and you scratch each other’s back once a month or so.
Invite Griselda over for the morning; she’ll miss her tweets and eMail, so she’ll not hang around for ever. That puts a time limit on the face-to-face stuff.
Tell Griselda BEFORE she comes over that the spreadsheet is free, but if she feels bad about it she can buy you lunch. (Always order the corned-beef sandwich with spicy-fries; you can eat only half of it anyway; bring the other half home for a second lunch tomorrow).
Tell Griselda BEFORE she comes over that you’ll support her in her endeavors up to an including the last day of the following month. That’s anything from one to two months hand-holding.
But tell Griselda BEFORE she comes over that after the end of the first complete calendar month you’ll charge her for support at 50% your regular rate, payable by retainer in advance.
Is that Asking Too Much?
I think not.
Griselda is acutely aware that she is "imposing” on you, and you on her; but as well she values your friendship and hates leeching off you; as you do her.
This establishes, up front (“Good fences make good neighbors”) that a no-strings freebie is being offered, and accepted, but that if the task becomes onerous, you will be recompensed without placing a burden of guilt on here.