A few weeks before you know your maternity break is done, you should begin pumping regularly to not only get used to your pump, but to get a stash of milk together.
I would suggest to pump once a day. The morning tends to yield the most. But keep in mind that you are right now feeding your little one full time, so an output of 0.5-2 ounces is totally normal.
"Should I take any supply boosters?"
Be warned, supplements come with their own side effects (fenugreek is bad for diabetics as an example). You really should research them before taking. Also, know that they will not help unless you remove more milk from your breasts. Lastly, you really don't want to boost your supply too much as the amount of milk being removed from your breasts during a work day should roughly be the same as what your little one will be nursing. Oversupply sounds nice, but it definitely comes with its own set of problems.
"How big should my stash be?"
If you think about it, you really only need enough for the first day. That's an average of 12 ounces. It is nice to have a little more, but really not much more is needed. Each day you work you should pump what you need for tomorrow. If you have a large stash, you may feel less pressure to get the amount right because you can just dip into your stash. And sabotage your supply. If you aren't pumping enough at work, you should immediately begin troubleshooting why. Is your pump not working properly? Do you have the wrong size horns? Is your daycare provider over feeding? Do you need to pump more often?
Unfortunately many times mamas that have huge stashes don't do this until months have passed and their stash is cashed and their supply has regulated down. That will be much harder to rebound from.
If I were starting fresh today, I'd aim for a stash of 30 ounces. Enough for 2 days and an emergency bottle or two for date night. But remember, anytime you dip into your stash, you should be pumping to replace that milk.
