People mostly use craft foam, wonderflex, or paper mache (ok, ok... PAPIER! lol), and you can use that for your armor and shield. There's a couple of good craft foam tutorials online (I have them saved on my home PC, so I'll post em later).
For gems, you can use a flat blue layer and put a transparent mould over it to give that transparent/gem-like effect.
For his boots, you can wear normal shoes under and design something that you can use as shoe covers (make sure you make it a bit heavy on the sides, so your normal shoes won't peek out).
There's a lot of ways/materials you can use, so it all depends on what your comfortable with, what's readily available, and what's within your budget range. I remember working on Ahri's ninetails last month, so I just had to throw the last one in there :P
Lastly, you can join the League Cosplayers group on FB -- facebook.com/groups/leaguecosplayers. They're a really helpful & encouraging bunch! One member did pink taric, so he might be able to help you better... and there's a Talon who's really good at making gems (he worked on an ezreal one, and stuff for his talon cosplay that you can use for taric's gems).
Best of luck to you, fellow Taric user!!! Cosplay is truly, truly, TRULY OUTRAGEOUS business!