Audrey - Dave might disagree or add more context, but I think that predicting 5-year rent growth is a bit like forecasting the stock market 5 years from now. 

With all of that in mind, I think it would really be dependent on where you see that specific market going.

Replacing a bathtub with a shower can make narrow bathrooms feel larger and more modern.That said, consider keeping at least one bathtub in the building for market appeal, as families with small children or certain renters may prefer it.

Most land buyers who are developers usually stick to a very predefined region within their local market and they hunt and wait for killer deals and market swings to get the land they want for the very specific purpose they want.

We rent to plenty of S8 applicants; I've always believed the standard of care they exude is as high if not higher than "market" applicants because they'll get kicked out of the program if they don't.

What are the amenities that people will crave in your market? 

But from my limited time in the game, I’ve found that my complete lemons are cash cows a few years later as market rent comes up well and my cap ex fixes a few years ago have paid off.

More than what I could get on the open market.  

Study the market.

I've done pretty well as a relatively novice investor in the stock market, just investing in S&P 500 tracking index funds.