Frizz can have a number of causes. A few ideas to try:
Clarify to "reset." You can use a silicone-free sulfate shampoo for maximum results. You can also try an apple cider vinegar rinse, which won't remove buildup per se, but gives some people amazing results.
Protein treatment and/or deep conditioning treatment. Protein will really depend on your hair properties (texture/width, porosity, etc). But many people find that taking some time to give hair a little extra TLC can make a huge difference.
Hard hold gel. LA Looks Sports Gel is a good option. Deva AnGel (Light Defining Gel) doesn't have a lot of hold, so you might find that you get more frizz with this one. If you live in a cold or very dry climate, you might want to check out LA Looks Power Spikes as an alternative to the Sports Gel (LALSG has glycerin, which some people cannot use in low dew points).
As far as silicones and sulfates... Silicones can be identified on ingredient labels by looking for those ingredients that end in -cone, -cane, or -xane. Silicones that have the letters PEG or PPG are water soluble an can be used with conditioner only cleansing. Contrary to the previous post, coco betaine is not a sulfate. It is a gentle, non-sulfate cleanser that is capable of removing silicones and preventing silicone buildup. It can be found in a number of sulfate-free shampoos (low-poos) and cleansing conditioners. This is a great option if you have styling products that you like that contain silicones. There is an excellent Curl Chemist article that includes a list of silicones and what cleansers are needed to prevent buildup (I'm on the phone app and can't link it, but it's easily found using the search option- I believe the name of the article is along the lines of What's the Scoop on Silicones?).

Modified CG since 11/5/11
CLEANSE: CJ Daily Fix, DevaCare No-Poo, CHS Treatment Shampoo
RO: SS Caitlin's Conditioner, CJ Beauticurls Strengthening
LI: SS Repairing Protein Treatment, CHS Silk Leave-In
STYLE: Re:Coil, Curl Keeper, Deva Ultra Defining Gel, Curls Rock Amplifier,Sweet Curls Elixirs Okra Gel and Hard Hold Gel, SS Curl Enhancing Jelly and Firm Hold Gel