I'm in a similar situation to yourself where my travel is mostly for personal trips so I usually fly in WT or WT+ to keep costs down. Indeed the US domestic in F flights are a good way to gain extra TP. On a recent trip to MCO I did a day trip to MIA and bagged extra TP by flying in F, the extra £50 on top of a coach ticket was worth it to me for the TP, priority through security, drink and snack on the plane and first off at destination. I'll be moving to Florida in a couple of months and intend to do a couple of super cheap mini TP runs in order to achieve and maintain silver status. I think the lounge access and extra baggage allowance will be a Godsend on my hops back and forward across the Atlantic. I've also decided to book my next trip out there via a rather convoluted itinerary in order to gain extra TP. Not only does flying six segments to get to my destination earn more points than flying direct; it also gives me a cheaper ticket. Try looking at flights on ITA matrix (Google it for the link) to find cheapest dates and trips with extra segments. Also for the time being flights booked with US Airways, on a US code are currently crediting discount economy tickets with full fare TP, it's not known how much longer this will continue but I'm booking my next trip with US and if I get the extra TP it'll be a bonus, if not then it's not the end of the world.