I went to Houston Quilt Market last weekend and it was great! My tips have already been mentioned but I will repeat them for more emphasis.
We didn't need it this year but valet parking is so worth it.
We got a cute cloth bag from Moda on Thur night and carried it Fri & Sat. My back was killing me both days from carrying it on my shoulder. Sunday I used my backpack (that I had planned on using) and it made a huge difference.
My sinus/allergies were killing me (horrible headaches and upset stomach) and I haven't had that happen in years. Thankfully my sister had some Tylenol sinus and that saved me.
Y'all have fun!