I'm starting my first ever worldbuilding world with this small hot spot archipelago. It's at about 43 deg S on a world that is, for my convenience, basically the same as Earth. It mostly has a Csb climate, with Dsb above 2500m, and polar above 3500m, on the tops of the 3 main volcanoes, and a rain shadow (Bsk, I believe) on the east side of the biggest island. I'm having LOTS of problems figuring out where to put rivers. Nothing I do looks right. I read through the How to get your rivers in the right place thread about 5 times before determining I had better just ask y'all directly. I'm also not really sure if I have enough granularity in my elevations, but I'm imagining them as mostly smooth between the topo lines for now. That might also be part of the issue? My main issue seems to be figuring out where watersheds would be, and then the rivers mostly? seem to follow from there?
Here's the map so far, if a higher quality image is needed I can get one, I just didn't want to go unnecessarily big
Click image for larger version.  Name: islands-big.png  Views: 56  Size: 417.9 KB  ID: 123597

If it matters, the three tallest volcanoes are active, with mostly fairly long spaces between eruptions, and the little one to the east that barely breaks 1250m is the youngest of the bunch, and pretty active as well. The geology is mostly based on Hawai'i, and the climate is based on southern Oregon, as that's the closest real-world analogues I could find for those.