What would be the best way to preload a few subscriptions that I are necessary throughout my whole application?
I used to do it with a waitOn call (Iron Router), but that is quite “passé” now (using FlowRouter now)
Should I use template level subscriptions on my general layout template and then show a loader that way? Or just a Meteor.startup (but how to show a loader?)?
If you would like to be able to wait for Template.subscriptionsReady() to show a loading spinner or something, then putting subscriptions in your layout template would work best. But if you don’t care about that, you could also do a null publish and you won’t have to subscribe to it at all:
Meteor.publish(null, function () {
return Whatever.find({});
});