just as an FYI, if you buy vinyl at a physical store, like Michaels or Hobby Lobby or whatever, it is CRAZY expensive. You should check out Oracal 651 12x12 vinyl sheets on amazon. It is maybe 25% of the cost compared to what you pay in a physical store.
I've been through a few of these and they work great: 63 pack for $29
also, the silhouette contact paper sucks pretty bad if you do any dyeing with heat. you end up with more of the adhesive on the disc than you do remaining on the contact sheet :(
the vinyl transfer tape stuff you see in my gallery actually sucks and I don't recommend it at all. I use this stuff now and it is fantastic: http://shop.vendio.com/cncsigns/item/911402157/index.html
As for the vinyl itself, I use Oracal 651 vinyl that I get off amazon. they sell a 63 pack of 12x12 sheets for around $30 here: https://www.amazon.com/Ultimate-651-Starter-Adhesive-Assortment/dp/B01NADR97B/
It takes a bit of trial and error and lots of practice. Keep going!
It's Oracal 651 if that helps. This exact pack on amazon: https://www.amazon.com/gp/product/B01NADR97B/ref=ask_ql_qh_dp_hza
The craftables vinyl says press 15 seconds with teflon sheet at 300-315. I do that exactly and for longer and still have the decal coming off.
44¢
Ultimate Oracal 651 Starter Pack 63 Glossy Self Adhesive Vinyl Sheets (12" x 12", 63 Assortment) https://www.amazon.com/dp/B01NADR97B/ref=cm_sw_r_cp_apa_LvpdAbXGP35X7
Am I allowed to post that link? Is that the right stuff?