Before playing on ring tables I observe for a while to get a read on others tendencies. If most of players are already marked, then its not so important. The reason for this is simple. I dont like my poker with aggressive donks. So if the tables are full of them, I will simply find another one.
When first joining a table, I wait for my BB to come around. There is no particular reason apart from being out of position & that when I first started I use to get straight into it, only to get crap cards on that first round anyway.
If I have to wait for my BB only to get bad cards, then I would leave that table after a few rounds, because in the past I have found that it wont get any better on that table for the day. Same goes for if I dont hit any flops, I will tend to leave & try again another day. Losing a few coins is better than drawing dead all day. Besides there are so many tables to choose from on-line.