I don't agree so much with Sub.. Kids have to want something or most have no goals.
My suggestion is along the lines of Lumburg.... (but not sure how he turned so fucked up with a solid Mom). Instead of giving them empty fucking possessions, open up a joint account in each of their names. Give them access to the statements of these accounts. Designate if for College and cars. Every time you feel a need to drop a present on them, for Easter, Kids Day, Valentines day or some other commercial bullshit, drop $500 or $1k in their account instead. Let them know if they get a full ride to college, the money is theirs. Drop out of high school or no go to college, the money is yours.
Also, pay them, in this account, $100 for every A they get on their report card. I do that to my daughter. She has made one B in her life.