It cannot be denied: for many half-size bakes, you will need smaller baking pans.  Fortunately, these are not hard to find.  Here are details about the types and sizes of pans I use, as well as other equipment and supplies you may find helpful.  For your convenience, I've included links to things I've ordered from Amazon, but they are not affiliate links.  

Layer cakes:  To make half-size layer cakes, you need 6-inch diameter cake pans.  Mine are from Wiltons, like these.  

Angel food cakes:  To make a half-size angel food cake, you need a 7-inch pan.  I prefer the type with a removable bottom and little tabs for cooling.  This is the one I got.  Angel food does not bake well in non-stick pans.  You can also use a 9x5 loaf pan instead; you won't get the traditional shape, but the same recipe will work perfectly well.  

Bundt cakes:  To make half-size bundt cakes, you need a 6-cup bundt pan, like this one.  This pan is also good for making half-size pound cakes.  You can substitute a 9x5 loaf pan instead.  

Measuring spoons:  Small bakes sometimes require really small amounts of ingredients, like 1/8 teaspoon or even 1/16 teaspoon.  If you have a 1/4 teaspoon measuring spoon, you can probably make do, but I find it helpful, and quick, to be able to measure small amounts directly.  I like this set from Prepworks.

Gluten-free flour:  Most of the recipes on this site are gluten-free.  I use a couple of different kinds of gluten-free flour.  My favorite for baked goods in general is this one from King Arthur.  I sometimes use teff flour when I want a more whole-grain effect.  I find this one from Bob's Red Mill to be excellent.   Teff flour is also excellent as a gluten-free thickener for gravies and sauces; it thickens nicely and also adds some depth of flavor. And it's an excellent source of nutrients as well.