How do you know you’ve reached a meditative state? How do you feel physically, mentally or spiritually? What are the signs that you’re meditating effectively?

For me when I know I've reached my meditative state, my whole body is relaxed, there's no tension throughout my whole body, my breathing has changed to deep long breaths, my whole focus is inward, the best part for me…. My mind is clear. Most of the time I'm so relaxed that I fall straight to sleep after my meditation.