Sugar gliders were originally wild animals. They will show their natural wild instincts by crabbing, biting, fussing, nipping, lunging, and running away. You need to understand from the viewpoint of your glider how they feel. Do NOT use any negative feedback when working with your glider. NEVER do anything to your glider that makes it feel anything but totally safe with you. These would include: hitting, popping, tapping the glider, placing it under running water, or confining it and wearing gloves. The glider would get more and more defensive.
Time, Patience, Persistence, Consistency, and Love are what it takes to have a bonded and trusting sugar glider companion.
When your new sugar gliders first come home give them a couple of days to get acclimated to their new environment in their cage. This gives them time to to relax. You can hand feed treats through the bars of the cage if they will take them (grapes, apples, yogurt treats, mealworms, licky treats such as yogurt, honey, applesauce, etc.). Speak softly to your sugar gliders so that they get used to your voice. It is even suggested to hum Silent Night as it calms them.
Have a daily routine for bonding. Being nocturnal they usually wake up between 10 and 11 o'clock at night. The best time to interact and bond with them is when they are still sleepy. Plan to spend a couple of hours daily bonding with them. Tuck pieces of fleece in your shirt to absorb your scent and put these in the pouch and cage of the glider. Replace frequently. This will help the glider to become used to your scent. You can also cover the cage with a shirt you have worn to make the scent in the cage stronger. Wear your sugar gliders in a bonding pouch for several hours or more during the day while they sleep. Pet your sugar glider often while in the bonding pouch or offering treats. Rubbing your glider on the outside of the bonding pouch is a good way to begin bonding.
Another good way to increase bonding quickly is to use a pop-up tent. You can let the gliders run all over you and the tent without worrying about their safety. They will use use you for a springboard and quickly trust you more and more. Many people use a tent (or a glider-proofed bathroom) for daily play time.
Some sugar gliders need more time to bond than others. Don't get frustrated. Go at their pace and back up a step if that is needed and then move ahead. Continue to use treats and positive reinforcement and you will have an incredibly rewarding and amazing partner for their entire lifetime.