This is my first attempt at a tutorial, so please feel free to comment or question if something doesn't make sense. I'm using US terms.
Here goes . . .
Create a magic ring, there are lots of great tutorials on the web so I didn't take photos - just google.
Round 1: ch 3 (this counts as first dc) then 1 dc, ch 2, then 2 dc. Basically, you are making 6 clusters of 2dc with a ch 2 space in between each. You'll have a wheel with 6 spokes.
Round 2: slip stitch into the first ch 2 space, ch 3 (counts as frist dc), then 2 dc, chain 2, then 3dc. You will stitch 3 dc into each space around, for a total of 6 3dc clusters.
Round 3: change color, join in any ch 2 space, ch 3 (counts as first dc) 2dc, ch 2, 2 dc, ch 1, then in next space, 3dc,ch 2, 3 dc (you are stitching 3 double crochet cluster, chain 2, 3 dc cluster in each space around, totaling 6).
Round 4: change color, join in any ch 2 space, ch 3 (counts as first dc), 2 dc, ch 2, 3dc in every space around. You will have 3dc clusters seperated by ch 2 in Every space.
Round 5: change colors, join new color in any ch 2 space, ch 3 (counts as first dc), 1dc in same space. Now we are working out of the stitches of the 3dc cluster. Stitch 1dc in the frist of the three cluster. Now, you will stitch 2 dc in the top of the middle of the 3 dc cluster (see photo), then 1 dc in the third stitch of the cluster.
Continue stitching 2 dc in each space, then repeating the 1dc, 2dc in same stitch, 1 dc in the 3 dc clusters all the way around.
Round 6: Join new color. Join new color between the 2dc in the middle of any 3 dc cluster.
Chain 3 (counts as first dc), 6 dc in same stitch for a total of 7 stitches .
Slip stitch in between the 2dc in the ch 2 space (photo above). This creates a fan.
Wrap yarn around needle and insert in to the space between the next 2dc stitches at the top of the 3dc cluster, stitch 6 more dc into same space - continue this around and fasten off. (When you fastern off, you need to secure the first fan stitch).
Round 7: change colors. Join over slip stitch of previous round.
SC in next three stitches, then 3sc in 4th stitch of fan to round corner, sc in next 3, slip stitch over the slip stitch of the previous round. You are basically outlinging the previous fans with sc.
Continue all the way around.
Round 8: Change color, join in middle stitch of the "peak" of the previous fan. (You may want to work in the back loops only here. I think it will have a neater finish than mine in the picture here.)
Ch 3, (counts as first dc) then 2dc in same stitch. Ch 2, skip the next 2 stitches, then treble crochet (tc) in the next 3 stitches. ch 2, then 3dc in the top stitch of fan, all the way around.
Note: If you work out of the post of the stitches, (not the back loop, but behind that even) you will have a nice chain outline that adds more dimension to the mandala. I've added a few more photos showing that option.
Working out of the posts, not front or back loop:
Round 9: Change colors. Join in any stitch. HDC in each stitch, and 2hdc in ach ch 2 space all the way around.
Round 10: change colors. Join with a sc, then chain 4. Slip stitch in the first chain of chain 4 to create little picot.
After you make the picot, sc in the next 2 stitches, then chain 4, slip stitch in the 4th chain, then sc in the next 2 stitches all the way around.
Ta-Dah! all finished.