is your home secretly leaking heat? here's how to tell

Was just reading this news story about a family that discovered their insulation was so bad they were basically heating their whole neighborhood, haha. Their energy bills were through the roof (pun intended), and they only noticed cuz of ice dams forming on their gutters and weird cold spots inside the house. Got me thinking - wondering if my own place is secretly leaking heat too. Anyone here dealt with something similar or found sneaky clues like this in their own home?