LAX is a big airport. When I travel through it, I look for shops. Typically airport shops pay more since there is a much more limited cadre of available shoppers. Some airports seem to have issues. I am regularly bombarded with entreaties to complete shops are small airports in Central Pennsylvania and Long Island. You may need to be more flexible with the timing requirements, both for performing and reporting the shops since people are getting on airplanes and may not be able to meet normal deadlines. Pay particular attention if the shop is in an international terminal, or the flyer is beginning an international long-haul flight. Many of MSCs ask for the flight date and flight number and whether it is an originating or connecting location for the shopper. There is more risk involved. If I am scheduled to complete a shop during a layover at Dulles, and the airline decides to re-route me through Chicago, then there is not way that I am going to be able to complete the shop at Dulles. And the first time I get a citation because a flight was cancelled, delayed, or I was rerouted, will be the last time I ever apply to do a shop for that MSC. If you ask me for flight details, and I provide them, then the burden of assuming the risk (of a cancelled, delayed, etc. flight) that I can't do it is on you, not me.
Some shoppers are willing to buy a completely refundable airline ticket. That generally involved fronting hundreds of dollars and may need to be done weeks in advance to ensure that you really have the reservation. Airport shops which I have done typically pay for parking. An hour of parking at a big city airport would wreak havoc on shopper fees. I have also been allowed to apply the parking fee reimbursement towards the cost of an airport shuttle.
There is more that I could write, but this should give you food for thought.
Shopping Southeast Pennsylvania, Delaware above the canal, and South Jersey since 2008