How long does one need to wait after getting salon coloring before using henna? I know there can be some kind of reaction of the two if they are done too close together.

Thanks! One of th sites you mentioned says that neutral henna isn't henna. I wonder if the same time frame applies to that, since that is what I am thinking about doing. I have super light blond fine hair and I also have eczema on my scalp. I heard that neutral henna is not only good for your hair but also helps the scalp. All those medicated shampoos help but they also leave my hair a weird bluish-ashy tint and then I have to go to the salon and get it corrected! It aint worth it!

I hennaed my hair about 2 weeks after dyeing it with chemicals.  My hair is also fine and blonde.  I used half henna and half 'blonde henna' which you know from reading the Mehandi site is another plant and not really henna.  The henna made my hair stronger and softer. 

I have used it 3 times now, each about two weeks apart to get to the color I wanted.

Mix the henna with hot, but not boiling, water or tea.  Too much heat will kill the dye.  Then let it sit out for anywhere from a few minutes to overnight.  If the henna is old, it will take the dye longer to release.  You can tell the dye is releasing when you stir it and it is a different color underneath the surface.  Some people leave a paper towel on it to see when that starts to pick up the color.

If your hair is already very dark, it may not be too noticable at one application.  The first two times I used henna, the red was gone from my hair within a week.  The third time was about 2 weeks ago and my hair is still really red. 

You can also apply heat to the henna while it is on your head to speed up and intensify the dye.  Put a shower cap over it and heat it with a hair dryer or use a heated cap.  I made a lazy, cheaters sort of dryer hood last time.  I laid a towel over my head like a hood and clipped it under my chin with an old plastic clip.  Then I just balanced the hairdryer on my shoulder under the towel and read the message board for a while.