I dye my hair fairly often and to get the best colour results I normally use a peroxide based product to lighten my hair so that the new colour is really vibrant.

For years I've used Jerome Russell products and a favorite of mine is the Bblonde hair lightener.
I normally use the light/medium version of this but they also have a medium/dark which has a slightly stronger volume of peroxide.




The kit contains:
Bblonde cream peroxide
Bblonde high lift powder bleach
Bblonde Shampoo
Gloves, Development cap, Tinting brush/hook and mixing tray

To use put on the gloves and mix the cream peroxide with the powder bleach, I use a tinting bowl and brush to mix this with but the one that comes in the packet does the job just as well.
 

I don't use the Bblonde kit as my final colour, just to brighten my hair before I use another shade on top, because of this don't need to use this all over my hair. I prefer to use a highlighting cap, by doing so it means that my colour will be multi faceted and blends with my roots much better.
You can buy highlighting caps in most chemists and supermarkets, the one I'm using is from Jerome Russell.
To use this brush your hair back as if to put in a ponytail and then place the cap on top pulling the front as far back as your hairline. Then use the end of the tinting brush (or a metal hook if you have one) to pull sections of your hair through the holes.
Then apply the product all over the hair you have pulled through then cover your hair with the plastic development cap
 I normally leave this in  for about 20-30 minutes checking every 10-15 minutes and massaging the bleach into my hair to make sure I get an even colour and don't miss out any bits.


 Once rinsed out and then washed with the blonde shampoo I also use an intensive conditioner, (normally Aussie 3 minute miracle) to make sure my hair stays in good condition as lightening products can often make hair a little dry.

I'm always really pleased with the colour I get after using Bblonde, I normally use another semi permanant colour over this but at this stage it would be fine to leave the blonde as is.

Jerome Russell BBlonde hair lightening products are available on the Jerome Russell website and most Boots and Superdrug stores in the UK as well as most major supermarkets.
The products cost between £5-£6 for each box.

The website also also has application techniques and "get the look" ideas for some gorgeous hairstyles.