I had always shy away from bare thread tatting for two reasons;
1. I always had problems with estimating the amount of bare thread space to leave at the start of each new ring; and
2. How to add new thread when the shuttle thread runs out.
I still have issues with No.1 but have conquered No.2. Sharing here is my method of adding new thread without making a knot.
In almost all of my shuttle-only project, I tat the first ring by folding the beginning thread end and tat the first few double stitches over it. This is not a new technique. Jane Eborall shared this method in her techniques website, http://janeeborall.freeservers.com/StartRingCatchThread2.pdf
I will come back to the reason why I start this way later, but you can get the idea after going through the following steps.
And now, the reason for starting with a loop at the first ring. After I have completed the flower motif, I will draw the tail end through the loop and do as in Step 4. This way, if I need not have to add new thread midway in the motif, I will only have one end to hide as compared to two ends.
As an additional note, I also use this loop in the first ring method to add a second colour to my project without tying a knot.
I do not pull the loop completely after adding the second colour. I keep the loop visible so that I can use to 'tie-off' one end of the project (by way of Step 4), while the other end is tatted over in a chain. This method of hiding in a chain is explained by Jane Eborall, http://janeeborall.freeservers.com/HidingEndsNoKnot.pdf
By this method, I only have one end to hide at the end of my round or motif or project.