First of all, clear everything that can be in the way. It makes wiping easier.

Sink: Before I grab any cleaner, I do a dry wipe down to remove hair, dust, etc. You can clean the faucet aerator(?) with a brush and vinegar to break down any hard water buildup. For the sink itself, you can use baking soda and dish soap, but I personally like using a bathroom cleaning product. In the small areas you can't access with a sponge or a rag, use a toothbrush. Make sure you clean these areas, because bacteria build up there like nowhere else.

Warning: Don't use harsh chemicals like vinegar on marble. In this case, use dish soap.

Toilet: First, dry wipe. Use a mixture of one cup of water and one teaspoon of dish soap, or a general-purpose cleaner. Spray everywhere and wait a minute. Use toilet bowl cleaner for the inside, wait a minute and brush all over the inside of the toilet.