First rule, no one values anything that didn't cost them something. You're being taken advantage of because even though they may want your time, knowledge and e

First rule, no one values anything that didn't cost them something. You're being taken advantage of because even though they may want your time, knowledge and experience it isn't worth anything more than free to them. I've been a consultant for over 20yrs and run into this with current and past customers alike. I've even been asked to bogus interviews just to be asked questions to problems they're trying to solve. I handle this by plainly stating my value and bill rates up front letting them know my time and experience is valuable. While I usually entertain a certain level of discussion I'll typically ask more questions of them about what they're trying to solve rather than just answering their questions or giving away solutions. If they need more of my time or assistance I say I'm happy to help, let them know my availability and will offer to draft a statement of work if they want to proceed. This will weed out those looking for a free ride from those who respect you and take you seriously. If you're already working for a customer and they ask for your help in a totally separate area, same thing applies offer simple advice if asked, but if it becomes additional work they task you with ask for a change scope to the current statement of work and adjust your rates or hours accordingly and set proper expectations for delivery of current and new scope. Best of luck.