First time grafts are always tense. Especially if they are seedling grafts. It can be an exciting process and it can be very tempting to touch it and look at it every day or two to see if it has taken or not. One of the biggest things that I've learned is that the more times you touch it or even pick up the pot to get a closer look, the more of a chance you will have of bumping it and destroying any chance it has of taking. Try to resist the temptation to look until you hit the two week mark.
Other than not touching it or playing with it the biggest tip I can give with my limited grafting experience is to have a clean work area with all your tools and everything you need laid out before starting. Also, work quickly, precisely, and as cleanly as possible as if you're performing surgery. It is best to have all your cutting tools sterilized and to try your best to make sure that each of the cuts are done close together in time, like within 30 seconds of eachother. The fresher they are when you place the two pieces together the better.
If you don't have steady hands it may help to brace your wrist on the table, a book, or something similar for added support. If you've knocked it off a few times I'd recut a paper thin layer off each side before 'replanting' so that the two are as fresh as possible.
Good luck. I hope it takes for you.