I learned the importance of advising ATC of alititude changes my last day trip. The exchange went something like:
Me: "Skyhawk 12345 descending to 3000ft"
ATC: "Skyhawk 12345 maintain VFR at or above 4000ft, traffic 12 o'clock, 5 miles, 3000ft"
Me: "Skyhawk 12345 VFR at or above 4000, looking...