There really is no homemade substitute for weed grinders like the ones featured on this site, however there are a couple tricks that can hold you over until your grinder arrives.
One homemade technique is to use scissors and a shot glass. It can be somewhat of a pain to get the optimum density and you have to be very careful not to spill it everywhere, but it is better than using your fingers. This method tends not to work so well for dense and compacted buds.
Another homemade option is using an electric coffee grinder. It will do a better job on dense buds than the scissors, but with this method you have to be extremely careful not to over do it. With a coffee grinder is far too easy to turn your buds into dust.
The best method is without a doubt purchasing a real weed grinder. You never have to worry about spilling or overgrinding, as the grinder will always deliver perfectly ground buds every time no matter how dense or sticky. In addition, most grinders have a kief catcher that will collect the highly potent pollen crystals that fall off during the grinding process.