It has been a good strategy for obtaining properties in the past. I will do direct mail campaign and will just drive my target areas. Look for clues, shabby yard, electric meter tagged as off. Check county records find out who the owner is and search to find any clues about them. The more that i know when it's time to negotiate the better. When i write my letter (sometimes i find there number and luck out and just call, i seal more deals this way) I try to come at this as a professional and address it like it is it's own business offer.
Tax sale is another way to obtain wholesale properties, it's trickier as you have to contact these people before the tax sale and close. You can usually pay off a year and some and they will then let you be for while, lol. anything bought after has clouded title.
Network, just having a group of wholesalers is a great way get deals and even sell yours to other wholesalers.
I do a direct mail campaign about every quarter. Tax sale in the summer and get a couple good deals a month from networking. Deals on MLS in spring and summer in my areas i target are slim.