Pooling samples for multiplexed sequencing has become the norm for many researchers, especially in the light of 1TB sequencing in 6 days! However many users struggle to get pools nicely balanced. I've just seen a tool I think is helpful so I thought I'd share it with you.
Agilent already provide the Bioanalyser which hopefully anyone who's pooling will already be aware of and will be using to accurately determine total fragment length (not just insert). You'll need this length to get the best out of a replicated KAPA Illumina library quant qPCR. After these steps you can calculate the nM concentration of each library, but then you still need to pool them, which most protocols would handle with a two-step normalisation and pooling.
Agilent provides a better solution in their QXT capture manual "Featuring Transposase-Based Library Prep Technology". Simply use this to combine libraries so each indexed sample is present at equimolar concentration, by pooling volumes as determined by the calculation. They provide an example table for multiplexing of four libraries (see below). The neat feature of their method over those I've used or seen elsewehere is that normalisation and pooling are achieved in a single step. Enjoy!