In these cases, obtain the clock from a debounced switch while debugging. This will allow you to observe signals for a long period in between clock transitions. In Summary Know what your circuit is supposed to do when you enter the lab. This includes a knowledge of all state transitions and critical clock edges. Be careful when wiring.
More time is spent looking for improper connections than any other single problem.
Be sure all power and ground connections are correct. Break complex circuits into simpler blocks. You must observe intermediate values. Use an oscilloscope where possible. Voltmeters and LEDs are second-rate probes.