Having trouble with streaking

Hello

People have told me on these forums that the best way to do streak effects is to use a toothpick and dip it into paint, poke the model and brush down with a brush that has only been dipped in thinner

I trialed it and it wasnt as good as I had expected. The thinner either killed away the paint when I brushed down and made a mess on the model, or I brushed away a bit of thinner and I brushed down and the paint didnt move at all it just stayed as a dot or it was rarely succesful but there was a lot of excess thinner and I tried to wipe it away but there was still shiny stainy thinner sticking out like a saw thumb

How do I fix all of this?

Thank you a lot