For extracts I like to use quarter pints. I feel like using anything larger makes too much extract and wastes a perfectly good jar.
For the citrus extract: I just took the zest off of 2 lemons, 1 orange, and half a grapefruit and put them in their respective jars. Fill it up with vodka (90 proof), cover, shake, and keep in a dark place. Shake every so often. After a month or so, check the extracts. If they are at the flavor of your liking, strain and bottle. If you would like, if it's too bitter, you can add a teeny, tiny bit of sugar to the extract.
For the vanilla extract: I cut the ends off of three vanilla beans and sliced them down the middle. I then cut them into fourths. I placed the bean in the jar and filled the jar with vodka, cover, shake, and keep in a dark place. Shake every so often. I don't strain the vanilla bean when the extract is ready to use. When I bottle the extract, I keep a vanilla bean or two in the bottle.
Top Left: Lemon; Top Right: Orange; Bottom Left: Grapefruit; Bottom Right: Vanilla