everything that i do they figure out on the spot.
You are probably expecting this response, but the most likely thing is that you are showing your tricks far too early before they are technically good enough and before your presentation is slick.
I haven't worried about a spectator figuring out how I have done something for years, and I would guess that applies to many of the more experienced members here, that is the easy bit. The hard bit is getting the presentation right so that a few moves thrown together become an awe inspiring piece of magic.
There doesn't seem to be anything wrong with any of the tricks you have mentioned, they should all be very 'impressive' so I am convinced that their falling flat is more to do with your performance of them.
I suggest that before you learn any more tricks you look into some of the posts here on performance, get hold of some books on the subject ('magic and showmanship', 'absolute magic' and the like) and watch other magicians (probably not David Blaine in this case as most people will find it hard to conect with an audience using a personality, or lack of it, like his).
On top of that, try to come up with a decent plot for your effects. I would put money on the guess that you predominantly talk through what you are doing when you perform (as most of us did to start with) and don't give the trick any context, leading to your audience mentally questioning why the hell you are doing this and coming to the ultimate conclusion that you are showing them a puzzle that they have to work out.
If an effect is presented properly there should be no question of your audience working out how it was done because they won't even try until it is far too late.
Of course it could also be because you perform for the same set of friends most of the time and they are actually going all out to catch you!
i dont know how to grip it to get the shape of the 'glass' just right
Hold the glass. Be the glass. Remove the glass. Close your eyes and hold the glass again.
Cogito, ergo sum.
Cogito sumere potum alterum.