When someone relines in the seat in front of me, I generally try to make a pain of myself until they get the message...

(1) I find that I need to get up and move around every 10-15 minutes. This, of course, means that I have to lean HEAVILY on the seat in front of me when getting up and sitting back down.

(2) I usually find that I am more interested in putting things in and out of the seat pocket in front of me. This usually involves jamming something bulky in there.

(3) If there's enough room available, I'll also begin to feel the need to put my tray table up and down a few times.

(4) Sometimes I begin coughing toward the seat while leaning forward, but only with the most inconsiderate of recliners.

That usually sends a message to those that feel they have a right to take the space in front of my face.