Based on what you said, it doesn't sound like a award reservation at all. If you made the reservation (under your name, I assume), then your clients "purchase" it, it is more like they were buying the ticket with $$ instead of miles. Anyone can pay for someone else's ticket under their free will. It's not in violation of any FFPs's terms.

In terms of award tickets, the miles have to come from the account holders who are making the reservation. Generally speaking, the availabilities of award seats are different from the revenue tickets. Hence you can't just find the available award tickets and make the reservations yourself. You have to use the right tools/search engines to know the award availability. That can be a very frustrating process, as SanDiego1K had pointed out.

As you are aware now, all FFPs forbit selling/bartering miles. It seems you tactically bartering your "services" with your clients' miles. If your clients ever use their miles to book tickets for you and get caught, the airline WILL cancel your clients' accounts and your booked tickets. The airline WILL ask you to pay for the ticket out of your own pocket. Being honest or not is no issue here. This scenario had happened and will happen. With all the selling miles/tickets on eBay/Craiglists, the airliines are really keeping a close eye on this kind of activities. I even read from the UAL forum their total legit award tickets (gifted to relatives/friends) got challenged and cancelled.

Given you are asking for input on such a public forum of your busines tactics, you are calling attention upon yourself. IMHO, it's not a wise move.

If you and your clients are willing to take the risks, well, good luck!