These are some antique pulls I have off
Here is a better picture for you. After I removed the paint I cleaned off the pulls with toothpaste. This is an easy and inexpensive way to clean hardware and jewelry both since you already have it in your home. I used an old toothbrush that I keep around since it gets into these little grooves great. This got off a lot of the grime but still doesn't get them really shiny since they have been badly neglected for years. Most items, this will shine them right up. Also, you can use white vinegar but I prefer the toothpaste myself.
To get the pulls to really shine up, use a product called Brasso. This is made to clean brass and remove tarnish. Now these pulls aren't solid brass, they are actually a die cast metal with brass plating so always be aware of what you are working with and test any chemicals on the back of your object to make sure that there isn't any kind of chemical reaction. To use the Brasso you will put the product onto your object and buff out with a rag. I recommend using an old one because the dirt that is removed while buffing out can ruin your rag. Now you can leave them like this if you'd like, just their original state.
Now I went further since I am not a brass fan. Here I painted the pull with a Turquoise acrylic paint. I prefer Folk Art but you choose your poison and which ever color suits your mood. Make sure to cover the pull well but don't let the paint glob up in your details because that's how you get how these originally looked. Also, Make sure to paint the backs where the pull will stick off your cabinet or furniture piece. Let dry. Acrylic dries fast so you won't have to wait long. You can use other types of paint as well but your drying time will be longer.
I then used Rub'nBuff Wax Metallic finish in Silver Leaf (this product comes in several finishes). You can find this in some craft stores, I just order mine off of Amazon.com. It is inexpensive and shows up at your door in a few days time. Now when using this, you only need a tiny tab on your finger tip and then just gently rub across the pull. If you apply too much at a time you will lose the effect of the color coming through. You can completely cover the item with the rub in buff to give a metallic finish. The product dries practically instantly, then just buff it a little to give more of a sheen. Now to remove product from your hands, you can usually just use warm soap and water but if you need something a little stronger use mineral spirits.
Now you can also try using the Rub'nBuff straight onto the item without the paint. This lets the gold/brass color peek through behind the the silver. Another really great option if you want something that's a little more subtle then a bright pop of color. This also looks really great on the furniture.