It was our first time to go to Yosemite National Park so of course we had to check the internet for tips. What we found scared us - Bears! That they can smell food from a very far distance. As filipinos, we couldn't stand not having food around (Filipinos I guess are one of the most voracious eaters in the world) so we ended up not staying at the park for the night. We had to stay at a hotel about 30 minutes away from the gate of the park. But after the trip, with the intention of going back, I figured it was ok to stay there. Just keep the food locked up in tightly sealed cans. I won't forget that the next time. It's such a wonderful experience being there.
Fun Alternatives: keep food away in tightly sealed cans and wrap them several times so the smell doesn't leak out.
Yosemite Sightseeing Tours (YST) out of Oakhurst CA was truly worse than nothing. Not only did we pay to sit in a bus for several hours that couldn't even go to parts of the park, but we had to put up with mean-spirited tour guide with chip on his shoulder. Truly, avoid this company.
Fun Alternatives: Just take the free shuttle buses that traverse the park. You'll actually see more that way than on YST tour.