I don't do a single thing. The people who are managing the deal are the ones who do the work and hire the workers to work on site and such. They of course get an even better return during the sale, but I am happy with what I get for doing nothing.
My rental properties are paying me a decent passive income of about 6%, and additionally the total investment about doubles in roughly 5 years. Also the tax advantages are pretty huge with the depreciation and the ability to take the money from a sale and put it into a new property with no tax.
So say you start with an initial $100K investment. That pays back about 6K a year for 5 years and then turns into about 200K after 5 years which you then put into a new property and make 12K a year, and so on and so on.
So if you start with 100K when you are say 25, then when you are 50, you will have around 1.6M in property assets making you about 96K a year in passive income, where the depreciation on the property value and the assets in the property outweigh the tax on the income, so that income is all tax free. And that calculation is assuming you don't put even more capital in from some other source. Of course it's a roughly average return assumption. Some properties will do better and others will do worse, but it's been my experience that it's about right.
Of course this is only one of my investment baskets. I allocate roughly half of the income that I can invest into real-estate like this and the other half into low cost index funds.