Application Time

I've linked to this video so many times before but it's really great (it's an instruction film from schwarzkopf about their product blondme)
http://www.youtube.com/watch?v=-gK91KNNUHA
There are lot of other good videos on youtube about applying bleaching.

What is important is to use a good bleach and 20 vol developer (30 if you have really resistant hair) mix it into a nice creamy texture in a plastic
To make a good application you'll need help from a friend (it's very hard to make it yourself). Put up the hair in sections using non metal hairclips (metals except for aluminum can cause a bad chemical reaction that makes the hair melt)

Start applying bleach in the neck area (or the area where your hair is the darkest) with a plastic brush, make fine sections and make sure to not apply it to the root area about 2-3 cm from the scalp.
If you use 20 vol developer you shouldn't worry about if the application takes 15 minutes or so (higher volume developer like 30 or 40 works very fast, not a good choice if you're not a professional or really fast)

About 10-15 minutes when the ends and midshafts have started to lift you apply bleach to the root area. And then tell your friend to go thru the hair again to see if there are any spots that isn't covered with bleach.

After that let the bleach process in room temperature for 45-60 minutes or untill it's light enough. Do strand tests and reapply bleach on the strands if they aren't light enough.
If you're going for dark blonde you only need to prelighten to yellow, for light and platinum hair the hair needs to be prelightened to pale yellow (like the color on the inside of a banana)
After that rinse thouroughly condition and then apply a blonde toner in the shade you desire, demi permanent toners are great for prelightened hair permanent ones causes more damage to the hair cuticle which is not so good after bleaching.

Thanks for the reply. That's the video I'd seen (I knew I saw it about the forum but couldn't remember who posted it so thanks again).

There's a lot of information here. I did it more or less how you've said but it's not lightened enough yet at the lengths. The roots went pretty light though. I guess it's because I previously used an XXL colour and ocassionally (maybe once every two months) straightened my hair. Ah well, I shall contemplate my next move 🙂

I'm pretty sure another round of bleach will fix it.

Try to only apply bleach to the darker sections, it's not good to rebleach hair that is already lightened (to the right level)
The safest thing would be to use foils, there are lots of videos also about making foil highlights on youtube.
It's best to use long pieces of alumnium foils (it must be 100% aluminum) like 20 cm or longer if you have even longer hair. You can make your own foils by cutting aluminum foil with a scissor.

Put a pretty thin layer of hair in it the foil and then brush on bleach to fully saturate the hair (you'll need to go in both directions with the brush for full bleach saturation) then you fold in the sides of the foil to the middle and then fold the foil a few times upward untill it's small enough that you can get to the next section.

Do not put bleach to far up in the foil and don't overlap to the light roots, it's ok if you overlap a little but do not put bleach on the whole roots) which color are the roots? Yellow/pale yellow?

It's important to open up the foils every 10 minutes or so (especially at the end of processing time) to see what color the hair has to avoid overprocessing.

You can apply a toner straight away after rinsing and conditioning 🙂

Ah wow, don't think I can go wrong if I follow your instructions! Thank you so much! The roots were yellow, the rest a gingery-red colour. I've put some directions over it to even it all out and hopefully by the time the colour fades I'll be able to bleach again.