I use TIGI too, you can buy the really big salon size bottles in TK Maxx for around £10 and they last ages. I used to be an Aussie fan but I got through the bottles too quickly and the Tigi costs me the same in the long run. At the moment I'm using the Self Absorbed 'mega nutrient' range which I love.
I have quite long hair now and its highlighted, so I need to make sure I look after it what with w-day coming up. I also have found that not washing daily (as I used to do) has made a difference, I try to stick to three times a week now. Another thing which has made a huge difference is taking Perfectil once a day, they are vitamin tablets targeted to your skin, hair and nails.
xoxo
I've just started taking Perfectil too!

I keep forgetting to take them though as i'm not used to taking vitamins every day. I bought them on a three for two so worked out quite reasonable