It's hard to say without seeing your hair, but for long thick frizzy hair Argon oil is great. I straighten my hair, which is long thick and blonde and it comes up great. I put a bit of argon oil through it after straightening it.
I also sometimes use coconut oil - it's thicker and may make it feel dry at first but after brushing it through later it's amazing! My hair is also healthier and more manageable when I grow it longer. I find the 'no no' conditioners like dove and Pantene the best on my hair too but I don't tell my hairdresser I use them! She would kill me!
You can also buy shining serum but I can't think of the brand names - works best on thick hair and apparently very effective.
Good diet - my hair is always better when my diet is really good. Weather makes a big difference too. Humidity is not the frizzy-haired girl's friend!