Eric Bilderback If you what to raise the rents with one increase, one possibility is to agree to do some minor, inexpensive, cosmetic upgrades for the tenant.

Buying inexpensive properties (possibly condo/townhome or SFRs in a less desirable neighborhoods or in one of the smaller towns with an hour of the city) and selling it with seller financing. 4.

Maybe a nice handsoap.In the past, I had an inexpensive picture on the mantle to make the place look nice for the showing.

The result is a very inexpensive, very clean looking, weed free yard for less than $1000 and only a few hours of your own time.

As was posted above, I believe the most money is saved by troubleshooting problems rather than immediately calling in expensive professionals.  

What are some other inexpensive marketing avenues that have yielded success for others?

Getting rid of meth is not an easy or inexpensive task  

They're inexpensive and made to look vintage and really hide dirt and stains. 

If you go with 2, then if their washer/dryer dies and they don't want to replace it, they will call you and say that it came with a washer/dryer and they want it back. 3, is not a good idea because used washers and dryers are pretty inexpensive to begin with (and they are heavy enough to be a 2 person job to move them).  

Some great takeaways here from @Jay Hinrichs and @Mike Carino.I too have seen inexpensive new construction dampen appreciation on existing homes.