From metapundit.net, there's a new post with a list of a few "PHP Do-Nots" that he's picked up over the years and wanted to share.

I realise I haven't thrown my PHP readers a bone for a while. Lately, unfortunately, all my experience has been with how not to do things. Some of this has been my own fault, but a really healthy percentage has come because I am maintaining one horrible project and rewriting another even more horrid. So, a few pointers for you l3et coders out there: Don't do any of this stuff.

Items on the list include less than thought out design and a lack of knowledge about how to properly use a database.