I second the pumping while baby is nursing. When I worked & pumped, I would keep an Isis next to my bed and that first morning feeding was like gold - I could easily get 4-5 ounces while she nursed the other side where during the day I often could only get 3-4oz on both breasts pumping for like 30 minutes on my PIS.
If you don't have a job yet, you could also look for a job that would let you minimize the time you are away from her, or at least perhaps take a break in the middle and go nurse her yourself. I realize this might be hard, but you could keep in mind while you are looking. I made a commitment when I went back to go and nurse her at noon everyday during my lunch break. I drove about 15 min to be with her for 30 then back again, then ate lunch while working at my desk. I tell you it was the best part of my day and made the whole pumping thing easier since I had less to produce.
I found that as she got older, she never took more expressed BM than she did when she first went. When I quit work when she was 10 mo, she was still taking just 4oz in the morning, nursing with me at noon and another 4oz in the afternoon, with an occaisional 2oz snack right before pickup - the same amount she ate when she was 3 mo - as she got older she just upped the solids during the day and nursed more in the evening and at night. (I always sent an extra bonus bottle just in case she was more hungry)
Also, keep in mind that if you are pumping between nursing sessions (rather than instead of them like you will while working) you are not going to get as much as it will take a while for your supply to adjust to the additional load. When you are replacing a session, then you aren't upping supply, just retrieving it differently, if that makes sense.