I ordered a pack of 10 emergency blankets for $10 off amazon and hung them around my closet. Does it look good? No. But very affordable! Just used thumbtacks to hang them up.
It looks good, I use aluminium foil (35%/50% reflectivity) but emergency blanket are better they have 75%/90% Good luck!
Need to flatten out those creases. Use a non expanding builders glue and a rolling pin. Start at the top and work your way down