A standing dc (US) or standing treble (UK) is a technique to join another colour without starting the round with a chain 3 which is a good disguise for a treble but always noticeable especially if you always make the ch3 in the same place. You get a kind of skinny line in your work where you start each round.
I can't show you here because it would not be my work but I would like to nudge you towards the brilliant video tutorial at Moogly
Spot the start? I have been practising, look, can you see the centre grey, orange and burgundy rounds appear continuous, isn't that fabulous? My final round was a bit of a rush and the wool kept splitting but I will be making more of these coasters to hone my skills. You can try too...
Coffee Mug Coaster (UK terms,4mm hook,DK)
Row 1: Make a slip ring. Dc12 stitches into the ring. Pull ring tight. Fasten off.
Row 2: Join new colour using St tr.* Ch1, tr, ch1* repeat to end. (13 spokes)
Row 3: Join new colour with a st tr, 1tr in the same place *ch1, 2 tr, ch1* repeat to end.(13 clusters)
Row 4: St tr, 2tr in the same space, 3tr in each chain 1 space to end (13 clusters)
Row 5: st tr, 1htr in the same place, 2htr in each stitch to make a border.
Give this technique a try and let us know how you get on.