Backdrops
Backdrops are one of the most necessary and easy props to create. Buy a few yards of muslin fabric. It is available in white, off-white and black. Muslin can also be dyed to match any skin tone or clothing choices. To paint a scenic background, use a projector to transfer the image to your fabric then paint with acrylics. You can have several backdrops prepared for each season. Fabric backdrops are also portable and can be used many times.
Posers
Every studio needs a few posers to help create perfect portraits. Stools of various heights can be used for posing multiple people. They can also be painted to coordinate with any backdrop. Step ladders make great posers for children. Apply a decorative coat of paint to a wooden ladder and you have a multi-level poser perfect for children. Construct a pillow case from your muslin fabric and slip in an overstuffed pillow for a baby poser. A wooden sled makes a perfect poser for a scenic winter shot. A park bench used for landscaping can be incorporated into a spring or Easter shoot.
Repurposing
Almost anything can be repurposed to fit your studio's needs. Look through your inventory of holiday decor and incorporate your favorite pieces into your props. A small artificial tree can be used to add realism to a painted backdrop for a Christmas shoot.
When you have exhausted your resources at home, shop your local thrift stores. They are a great place to find items that will work in your studio.
Photography is an art form that can incorporate all of your creative energy. Invest some time and effort into your props department and you'll have the studio everyone wants to visit.