I'd have to argue as to the effective level of the paratroopers in both Normandy and Markey-Garden. The paratroopers, when considering what they were up against, performed very well. Consider that they are vastly outnumbered, in Normandys case many landed with no weapons, and massive misdrops made cohesion near impossible.

Market-Garden failed simply because Airborne troops are not meant to handle panzer divisions.Also take into account Market-Garden was expected to be young boys and old men, and turned out to be Elite Waffen SS units. Granted, Paratroopers themselves are often considered elite as well, but without armor/artillery they can only do so much.

As far as ways to make them better..there is only so much. Simple things like a leg bag that DIDN'T fall off when you jumped certainly help in the short term.

The problem is, they are greatly limited by what they are doing. There is only so much you can bring with you to jump out of a plane. I feel that paratrooper tactics were sound in themselves..but situations out of their control greatly effected said tactics. In the case of Normandy, dropping (in many cases) miles from where you are supposed to be, has a profound effect on accomplishing your objectives, and in most cases the Paratroopers did the best possible job considering their situation.