Question

as we know we can make things fly by magnetism but how?

Answer 1

Novelty items have made good use of this technique for quite some time, specifically as desk decorations. The concept is relatively simple, though tricky to execute.

Obtain a polar magnet (north/south) and place it flat on a surface. Create an opposing force using another polar magnet with the same side down.

By placing a third bipolar magnet between the two, you can use the force of gravity to keep it from attaching itself to the upper magnet. The repulsion effect of the lower magnet will keep it from falling.