What is the best thing to use in making this crown, fondant with tylose powder or gumpaste. I usually have a problem with fondant getting cracks in it when i use tylose in it. Any help is appreciated. Thanks!!

 You can use gumpaste or a mix of 50 / 50 gumpaste and fondant.

Thank you so much! Do you think I can just place it on the cake or should I use toothpicks/skewers to secure it?

 If the cake is travelling a distance it would not hurt to have a couple of toothpicks inserted in the crown so you can secure it to the cake.  You can also brush a little edible glue or piping gel to the edge of the crown and that will also help to secure it. 

Thanks will do!