Always pay by the night for hostels if you can
Whenever you can, pay by the night for the hostels. I always just say I need to run to the ATM. That way, if it is bad, you can back out after one night without losing any money.
After checking into my hostel which I THOUGHT had a kitchen (West End City Hostel), and realizing a bit later it did not, I am glad I paid by the night. I found another hostel with a kitchen and am going to go there tomorrow, assuming I get a bed (and it looks like they have beds, but I am going to call in a bit and confirm). Anyway, I also read a review on hostelz that several people who stayed there got bitten by bed bugs. I am going to use my own sheet on top of their sheets and hope I am okay. If I see anything strange, I am getting the heck outta there, never mind the money I paid. But please, pay by the night whenever you can.