Raised Treble Fronts are great, they add texture to your stitches and are used to make cables in crochet too. I used them to give the spiraling effect in my Hill Top Hat.
They are abbreviated to RtrF in patterns and in US terminology they are known as Front Post Doubles (FPDC)
Here’s my handy photo tutorial:
Please feel free to pin it for future use.
Remember that if you don’t want to increase, don’t work into the top of the stitch as well. (Although in my Hill Top Hat pattern we increase very neatly by working both around the post and into the top of the stitch.)