ALWAYSpedal when you shift. We do not want to tear up the derailleur
If your feet are spinning like a hamster, move your right bar shifter forward. This will put you in a higher gear.
If your feet are moving like a glacier, move the right bar shifter backwards toward you. This will put you in a lower gear.
Use one shifter at a time.
Small changes with the right shifter
Big changes with the left shifter
Cross chaining is where both gears, front and back, are both in the smallest sprocket OR both gears are in the largest sprocket. These scenarios will most likely critically damage the rear derailleur or lock up the chain. Most of the time, keep the chain in the middle gear up front. The left shifter controls the front derailleur.
If the up front gear is in the small sprocket, make sure that the right bar shifter is not all the way forward. If the up front gear is in the large sprocket, make sure that the right bar shifter is not all the way backward.