Don't let the professionals fool you. Ombre (or balayange) hair can be easily achieved at home. I'm not really sure how to go about writing a DIY for this because it's just kind of an intuitive thing. If you have any experience dying your hair at home, this should be a total breeze. Honestly, I refered to the DIY of LLYMRLS before embarking on this endevour and recommend that you do the same.
Here's what I used:A lightening kit/powder (NOT blonde hair dye...you CANNOT lift color with color). I used Clairol's Born Blonde kit from Walgreen's as it was late at night when I decided to do this and since I have very little patience, I couldn't wait until the next day to go to the beauty supply store.
A box of a light brown hair dye.
A toning kit that happened to be on sale at the time that I unfortunately cannot remember the name of. You can buy a toner at any beauty supply store.
And what I did:I started by following the mixing directions included with the lightening kit and applied the product on my hair with my (gloved) hands from about ear length down. As my ends were pretty much black to start with, I let the product sit for about 40-50 minutes. I occasionally checked the color and applied heat with my blow dryer. Once some noticeable lightness had been achieved, I washed out the product and dried my hair. I continued by again applying the bleaching product, this time focusing mainly on the ends of my hair. I also added product to a few areas around my face. Once again, I let the product sit (adding occasional heat) for about 40 minutes. Rinsed, dried.
At this point my hair was looking pretty brassy but a good deal lighter than what I started with. I then did an all-over light brown dye focusing mainly on my roots and the middle length of my hair. I decided to include this step just to warm up the portion of my hair that wasn't being bleached and to add a little color/help with the overall ombre effect. The processing time on the particular hair dye that I used was 10 min. Again, I washed out the dye and dried my hair. Finally, I used the toning kit that I had bought. The toner helped to reduce the brassy undertones and just kind of neutralized everything. Following using this kit, I again washed and dried...for the last time leaving me with what you see above.
The fact that ombre hair has a kind of beautiful imperfection about it makes it pretty easy to get right. With that being said, if you do decide to go about doing this yourself, please follow all directions included with the products that you purchase and, most of all, use your best judgement. I don't want to discourage you but if you are at all intimidated by dying/bleaching your hair at home, you might want to refrain from doing this. I'm really just saying this to serve as some sort of disclaimer...the whole process was rather easy (albeit time consuming) and is worth giving a shot.