I’m about to start a new pattern (Brooklyn Tweed’s Girasole) and I’m starting it with short dpns. After a while, of course, I’m going to have to switch to larger circular needles. I was just wondering if anyone had any tips on how to spot the right moment to switch. I don’t want to end up with too few stitches spread out over my needle.
When you get too many to handle on the DPN’s.
For me, I switch as soooon as i can!! So that means, when you think you have enough stitches to fit on the circular, you switch.
When there’s too many for the dpns to hold without being in danger of falling off. And you can just knit the changeover round with the circular, you don’t need to slip the sts onto it. If there’s still not quite enough sts to go around the circ, then you can use it and one or two of the dpns - just like you’re still working with the dpns only, except one of them is super long with a cord on it.
Or if you can’t figure out how that would work, you can use Magic loop (shown on the Advanced Techniques page) or the single loop method.
I generally switch over when I see the DPNs getting a tad crowded and I’m in fear of loops sliding off the needles. There is no secret rule, you just learn by doing. As is most of knitting. 
Thanks. 
I’ll have to see how it goes and try it out.