Okay, so from the You Tube videos you will have hopefully now seen all the moulds - the last one is actually a sugar craft mould - this you will find on Create and Craft or from Blossom Sugar Art.
I found the mould wouldn't work unless you cut the pieces apart (don't trim the ends off though, as these will help you line up the mould easily). I added mica powder to the top of the flower, then poured UTEE into the bottom half - don't be scared to over-fil, and then when you close the mould don't worry when the UTEE over spills. Allow to cool a little, then cut off the excess UTEE. You can shape the flower using the melt pot - gently touch any parts you need to melt on the side of the pot and the heat will melt the UTEE.
The leaf is something you may need to practice. It's just a little wire, wrapped and then left in a loop. You will dip this into the UTEE, and lift out, making sure you angle the wire. This will give you a skin of UTEE - it's very delicate, but really effective. The flower is also really fragile. Try with lots of different silicone moulds so see what effects you get.