I purchased some nice kitchen cabinets from Habitat and put a new counter top from home depot on them.

@Kusum ChanraiFor rental properties I buy my used cabinets at habitat for humanities.

Its a 1996 Habitat built home tho and by property info had only 1 homeowner (who apparently defaulted) and was recently evicted (on recent drive by, saw the eviction contents on front lawn). 

We are currently renovating the property and a man shows up and tells us that he still owns the property and has a grant from the habitat store for 40000 to renovate the property.

Volunteer at Habitat for Humanity to learn basic construction/improvement skills. 

The sink was from Habitat ($75), the wood was leftover from a butcher block counter, fabric from Walmart, shells and mirror courtesy of my MIL and a beach in Mexico.

you can go to job sites of new builds and get some cull lumber , you can pick up some deals at the Habitat for humanity type stores.

I often get good used vinyl windows from Habitat or recyclers.I usually buy and stock pile good used (standard size) vinyl windows when I find them for sale on the inter net.

@Anthony Madia Citi Habitats in Manhattan UES

If you want to learn the construction side of it volunteer with habitat for humanity and they are always looking for help.