There were plenty of real elements used in the PT, Lucas just doesn't want to admit it, so all the "making of" stuff focuses on the digital work. There's a convention I go to every year and for several years one of the guests was Carol Bauman from ILM. She showed workshop pics of ILM crew working on models of Coruscant buildings and various craft from TPM and AOTC (ROTS was still in production at the time).

Various digital FX animators, ILM and otherwise, have all gone on record as saying that natural elements - water, smoke, fire, rock formations, etc. - still take a lot of work to generate in CG and look convincing, so they have to resort to the old ways for those elements, at least for now.

No embedded images allowed, I see.

http://www.blissnet.org/ot.c/01.jpg
Naboo fighter model being 'sploded

http://www.blissnet.org/ot.c/02.jpg
No footage of them performing this trick. Same basic technique used in AOTC.

http://www.blissnet.org/ot.c/03.jpg
Miniature podracer hangar

http://www.blissnet.org/ot.c/04.jpg
Miniature Theed plaza

http://www.blissnet.org/ot.c/05.jpg
Podracer props

http://www.blissnet.org/ot.c/06.jpg
Dudes in masks

http://www.blissnet.org/ot.c/07.jpg
Animatronics

http://www.blissnet.org/ot.c/08.jpg
Speilberg and Lucas discussing the pro's and con's of battle droids vs. stormtroopers beside a battle droid prop.

http://www.blissnet.org/ot.c/09.jpg
Yeah yeah yeah, but what you might not have known is that some shots in the film utilize a guy in the suit. They're quick but they're in the movie if you look for them. For example, when you see Jar Jar's hand as he tries to fish the wrench out of Anakin's racer engine, that's his "real" hand.