1) Make all ADR's as soon as possible. I know it's tough to plan that far in advance, but especially with little one's - IMO it's better to have them than not.
2) Don't go too crazy with character meals. They are not relaxing at all, but fun. And with my family, adults and kids alike, we really didn't eat all that much - way too much picture taking, looking for characters, etc. So we limit them to a couple/few per week long trip.
3) That said, since it looks like you'll have a 2 year old without credits (if this is correct??), book lots of buffets. he/she eats for free here so you don't have to worry about sharing.
4) Use your snack credits. When we first started using it, we would try to 'save' our credits for something 'significant' and not just use them on water or soda or a bagel in the morning. But we found we would have too many leftover at the end of the trip. So now we use them as SOON as we're able. We always say that if we end up having to pay for one or two at the end of the trip that will be OK, but we always have enough anyway.
5) For best use of
DDP AND because of your kids' ages, I recommend bringing some cereal/other light breakfast items in your luggage. 1) It helps stretch your dining credits farther but even moreso 2) It saves a ton of time in the morning being able to grab a quick bite in your room and not have to deal with food court crowds/lines. When our kids were little - either dh or i would hop in the shower while the other dished out some cereal for the kids...then while the other showered the one who was done would sunscreen the kids...then by the time we were both ready we'd head right to the bus stop.
OK - I think that's my top 5 tips...
ENJOY It!!!