A couple of additional approaches I've had success with: - "I can (for you), but it involves me asking a few people for a big favor, so could you confirm with

A couple of additional approaches I've had success with: - "I can (for you), but it involves me asking a few people for a big favor, so could you confirm with your (manager / colleagues / friends) that they really want this?". I've found this a) filters out most low-value requests, b) gets your own contribution recognized. - "I didn't quite understand your email. The choices are A or B or C, what works best for you?". Don't anchor on their request, don't even mention it, just restate the choices open to them and let them choose. Particularly where there's a clear external anchor it elides any contrast with their request "well you said X, I can only do A, sorry there's such a gap".