Ok, I've done my tie-dye and I must say I'm very pleased! I'm a bit anal retentive so I had to actually go out and do it to start gelling with the fact that tie-dyeing really is an imprecise science of sorts.
I did a combination heart/scrunch using a squeeze bottle for the heart areas, squirting over the top while squeezing the wad some, then stabing the tip into the pleats a little bit, and dunking the rest, tied, in shallow yub of dye, holding it for about 4 or 5 seconds on each side, then gently squeezing out (and into the pleats) the excess dye.
The first wasn't as nice as I'd hoped, but still OK. I used rubber bands to tie that one, which really defined the heart outline, and used yellow for the center, hoping for a more orange blend. The second I was sure to really exagerate the heart more and I tied it with a kind of yarn instead, which resisted the dye less (more to my liking) and offered more control over the pleats, but I still used bands for the scrunch as I felt it was easier to keep tight thus. I used orange for the center of the second instead of yellow and added a surface application of navy blue to the scrunch to give it more depth.
All and all, I'm very happy with my shirts. The first is for me (the experimental one, of course) as the second is for my girlfriend, a major fan of tie-dye apparel ^__^.
Thanks again!
1st

2nd

**EDIT**
Sorry for the delay, everyone.
These shirts were done at school as something to do during AP Chemistry now that the test has passed and the year is basically over. Unfortunately, I didn't inquire much as to what supplies were being provided us. So I asked later, after the fact, to find...brace yourselves...
It was R.I.T. dye

So I've rinsed my shirts and lost a lot (since we dyed with cold water): gone is the killer contrast provided by the acid dye

, and the wonderful white, thanks to bleeding direct dye

(I've already ordered some Retayne to prevent further bleeding).
Rinsed 2nd

Yet, although I much prefer the way they looked before, I'm still happy with my shirts =D.