Modify a mower to be a garden mulcher
Here is a simple mower mod that makes it into an effective garden mulcher. This mower cost me 5 bucks - you can use your yard mower and it won't affect its ability to mow your yard as a normal mower. This is a two-blade mower, it will probably work far better if I mod it to work with four blades.
This works far better than the garden mulchers you buy from the shop.
Please use proper PPE when using a machine such as this.