It really depends on your model, end goals, etc.
Are you looking for constant deal flow in a particular area for your crews to work rehabs or to wholesale (say 3-5 a month?) Better be doing some direct marketing (yellow letters being my personal favorite).
Are you looking for one off deals to hold, only purchasing 5-10 annually? Networking will be your best method, IMO.
It really depends on how many deals you're looking for, for what purpose (i.e. exit strategy), and the types of deals.
Most those ideas you posted are fairly mediocre, IMO, but really, anything can work if you put the effort in.
Which book are you reading?
(EDIT: Nevermind, saw in
this thread you recommended Real Estate Riches by Dolf de Roos, I'm assuming that's the one you're reading.)