A sticking faucet is usually attributed to the beer drying up at the point of the seal of the faucet valve. Beer has enough residual sugars in it, that when the beer dries, those sugars glue the faucet shut at the point of the seal. If it only sticks on the first use after an extended period of non-use (24+ hours) then that is mostly likely what is happening. Darker heavier, malty (sugary) or homebrew beers can make this problem worse. To solve this problem, switching to a different style faucet like a ‘forward sealing’ Perlick faucet can help. To inspect and or clean the faucet, 1st un-tap the keg, then put a glass under the faucet and open the faucet to relieve any pressure. Use a faucet wrench to remove faucet from tower. Then unscrew the thumb nut that attaches the faucet handle to the faucet body. This will expose the lever and let you can inspect the condition of it. At this time clean all faucet parts thoroughly with warm water and a safe beer cleaning solution.