1 gallon batch question

When doing a 1 gallon batch in a glass jug do you add the 3lbs honey to exactly 1 gallon of water? that would essentially be more than would fit in the gallon jug correct? Or would I be better off mixing like 3lbs of honey with .75 gallons of water to get the batch right at 1 gallon?

If done the first way would the extra must be saved to use to top off secondary or tertiary(sp)if I decide to add some sort of flavoring when I rack to secondary?

I am thinking of doing 3lbs to 3.5 lbs of honey, water, nutrients, in a one gallon batches and add different flavorings when I rack to secondary.

Thanks for guiding this new bee!

Its 1 gallon total volume, so you only need .75 gallons of water

You're overthinking it. Add honey to primary, add other ingredients, top off with water to desired volume. Shake like the dickens and you're through, without any overage!