How to use Windstopper gloves most effectively?
They'll never provide as much insulation as ski gloves, on their own - they're not designed to.

They're intended to block the wind (so minimising the convection heat loss due to high airflow) but still allow you to breathe (which implies you still get the heat loss due to evaporation).

A wicking/insulating liner underneath will add some straight insulation too; if it isn't wicking or fairly open weave you'll lose breathability, but on the other hand an open-weave glove the wind would otherwise cut right through will actually be useful with these over the top.

For comparison, I sometimes wear a windproof shirt for running, usually in the winter: if I wear it over a singlet and it sits against bare skin on my arms, it doesn't add much (or any) warmth. If I wear it over a baselayer, it adds lots, while still being lighter than an equivalent softshell and more breathable than a hardshell.



tl;dr - use a thin, breathable insulating liner. Wool will probably work well.

Oh, and pay attention to the cuffs and your sleeves: any part of your arm not covered, even if it doesn't feel cold itself, will be losing heat that should be reaching your hands.