Only need a zester and ice cube tray and you have saved the whole fruit.
What I do:
I have been buying lemons like crazy, when on sale, then I wash and zest them all. Measure out by tablespoons, the zest, and put it in a small baggie, label and freeze. THEN I juice them, again measure out, and put in ice cube trays and freeze. When frozen I move them all to baggies, label for measurement and ingredient, and keep frozen until used.
My ice cube trays will hold about 2 tablespoons.........so that is the measure I do. If recipe calls for only one tablespoon, usually doesn't hurt to use two.
The zester is one of the best saving devices I have. I zest ALL citrus fruit............oranges, lemons, limes, even tangerines!
Learned this when I had to pay $7 for a bottle of lemon zest!!