Chose a road bicycle over a mountain bike. Road bicycles require you to put less pressure on your hip flexors and are lighter, making them easier to maneuver. You may want to choose a cruiser style bicycle, if you can currently sit comfortably. These bicycles allow you to maintain a more upright position and are typically more comfortable than other types of bicycles. But remember cruiser style bicycles often have only one gear and are far less aerodynamic.
Check the seat of a prospective bicycle. Always chose a bicycle with an adjustable seat. After hip surgery, you want to keep the seat of your bicycle slightly higher than normal to take pressure off your hips.
Measure your height. Make sure to chose a bicycle recommended for your height or shorter.
Take a prospective bike and straddle the top tube. You want about one to two inches of space between your bottom and the bicycle.
Sit on a prospective bike and grasp the handle bars. Make sure your arms have a slight bend.
Take the bicycle for a test drive and see how your hip feels. If you experience pain, then stop biking immediately. Resume trying bicycles after your body feels better.