A common choice is to use knobs for all drawers and pulls for all doors (or vice versa). The problem with knobs is they are harder to grip and fingernails tend to mar the cabinet door. It is much more comfortable to open a drawer using a pull, which allows the whole hand to grab instead of only your fingertips. We generally use pulls (no nobs whatsoever) in our kitchen designs.
One of the first reccomendations I give on choosing hardware, is on wide drawers. Go with a single larger handle especially in the kitchen. The kitchen is a busy area and users find themselves with something in their hand when they go to open a drawer with the free hand. If there are 2 pulls on a drawer, just using one will end up tweaking the drawer in the long run. When I begin to look for a hardware collection always look at the range of sizes in that collection. I like the rule of the larger the drawer the larger the handle... or the more weight the drawer will hold the wider the stance should be that the handle provides.
Black was a great color choice for the bin pulls used here on stained wood cabinetry. When choosing knobs, hold them against various finishes to see which color looks best. You may have seen a photo of a knob you love in polished brass, but with a different cabinet door color than the ones you actually own. Bin pulls come in almost infinite other finishes as well, including chrome, oil-rubbed bronze, cast iron and brass.
Let’s talk first about metals. As a general rule, I like to keep the different metals in a kitchen to no more than two. If you have stainless steel appliances, that counts as one metal. So that leaves one other metal you can bring into a kitchen. If you’ve got brass light fixtures, that’s your one other metal. Your new hardware should be nickel or brass.