For the squash I would let it dry out for a while. When it looks wilted in the morning then give it a watering with some diluted fertilizer. If it has a strength listed for containers on the label then follow that. If not then half the suggested strength. Then water with the fertilizer.

For the tomato it depends on the size of the container. If it is small enough that you can take the root ball out of without ripping it out you can take it out, wrap it in cloth to keep light off the roots, and let the potting mix dry out. Afterwards you put the root ball back into the pot. Wait to water till the plant looks wilted in the morning. Then water it. Keep the leaves dry. Water the medium. Not the leaves. Fertilize it as well. It needs nutes to do well.