Your bridal shower doesn't have to have a theme, but having a focus can make planning it easier. Themes can be as simple as a color palette or a time of year. They can also be as complicated and fancy as you like. I've picked a few of my favorite themes that can all be done on a sliding scale depending on the resources available.
Because brunch. Am I right? Brunch is pretty much the coolest thing there is these days. It creates the perfect backdrop for a relaxed shower. You can opt for a few tables at a restaurant for something small and intimate or you can host it at someones home relatively easily. Set up a make your own mimosa bar and a waffle station and everyone will be happy.
I love the idea of a tea party because you can make it really complicated or really simple depending on your budget and how much time and effort you can afford to spare. All you really need are a few tables decorated with fresh flowers, some mismatched teacups and kettles and tiny little foods served on tired trays. No matter how intricate or simple your displays are or how vintage or not your teacups are, guests will still feel fancy.
This one is a little trickier in that you obviously need a pool, but beyond that it doesnt require anything but nice weather. Cute oversized pool rafts were the biggest accessory of the summer and nows the time to collect them from clearance wracks and populate your pool with a little whimsy. Giant inflatable engagement ring anyone? Of course as long as you have good weather the best thing about a pool party shower is that guests can sit outside, enjoy a drink and keep things nice and casual.