hi i am new to the tee shirt community and i have some questions that i hope you guys can help me with

.. so i came to the conclusion of doing heat xfer vinyl. But i want to make it professional and willing to put the extra mile to make it that way. i was looking at a site before and saw a few designs i thought were pretty intresting.. and hoping if you guys know if this can be created with the process im doing and if not what technique..
and whichever printing method its using, could you guys explain how they came about making it like that? =] thanks!!