I use about 1 tsp in 1/2 cup water. Boil water in kitchen kettle*, pour into sanitized bowl. When it has cooled down a while, sprinkle gelatin into it. Let stand a few minutes, then stir until its clear and you can't see any more gelatin. Add it to fermenter 3 days before bottling. They say the colder the better, but I haven't got resources for that and just do it at room temp with acceptable results. Batch prime and bottle as usual.
I would assume that if you're kegging you could gelatin the fermenter and wait a few days, then keg it. It only makes sense to me that this would cause all the things that drop from suspension to not end up in your keg and you would be able to save those first few pints. All theory on this one.