How hard is it to highlight your own hair?

[Newjob12345]

I have highlights done at a salon but can't find a spare few hours where I could fit it in, so I thought about doing it myself.
Has anyone ever done it and it's not turned out disastrous? What do I need for a root touch up?

I did it and it turned out fine. I used a cap with holes in and pulled strands through.
I have no red tones in my natural hair so my hair does not go brassy and lightens very easily.
I used jerome Russel B blond. Pleased with the results and people are surprised when I say I did it myself. Cost me 6 quid.

I've also done it myself with a cap. I find it easy and I'm not the best when it comes to things like that.