How can I effectively cut tongue and groove joints using a hand router?

To effectively cut tongue and groove joints using a hand router, follow these steps:

1. Set up the router with the appropriate bit for cutting the joint.
2. Adjust the depth of the bit to match the thickness of the wood.
3. Use a straight edge or guide to ensure straight and accurate cuts.
4. Cut the groove first by running the router along the edge of the wood.
5. Cut the tongue by flipping the wood and running the router along the edge again.
6. Test the fit of the joint and make any necessary adjustments for a snug fit.