Even if you don’t possess a particularly unique talent, speaking English is a skill in itself – and one that many people are keen to learn. Online language schools like www.lingoda.com offer flexible virtual teaching work, making it possible to coach English from the comfort of your own home. If you’re looking to make extra money without working long shifts or taking the time to master a new skill, cashing in on your existing skillset is the ideal solution.
Dividend Income: Dividend income is wonderful because it is completely passive and is taxed at only 15% if you are in the 25%, 28%, 33%, and 35% income tax bracket. If you are in the 39.6% income tax bracket you will pay a 20% tax on your dividends. My dividend income portfolio mainly consist of dividend equity and bond ETFs such as DVY, VYM, MUB, TLT, and IEF. Total stock and bond income is a little over $100,000 a year due to a heavy accumulation of stocks and municipal bonds after selling my house.
One of the things I'm surprised your article doesn't mention is the tax advantages of this type of investment. The depreciation and rehab costs (purchasing distressed properties) can be huge deductions to ones income taxes, which none of the others have. Then, along with the appreciation of real estate, this passive income investment outperforms the notion of maxing out my 401k as well.
As interest rates have been going down over the past 30 years, bond prices have continued to go up. With the 10-year yield (risk free rate) at roughly 2.55%, and the Fed Funds rate at 1.5% (two more 0.25% hikes are expected in 2018), it’s hard to see interest rates declining much further. That said, long term interest rates can stay low for a long time. Just look at Japanese interest rates, which are negative (inflation is higher than nominal interest rate).

The citizens of the Indus Valley Civilisation, a permanent settlement that flourished between 2800 BC and 1800 BC, practised agriculture, domesticated animals, used uniform weights and measures, made tools and weapons, and traded with other cities. Evidence of well-planned streets, a drainage system and water supply reveals their knowledge of urban planning, which included the first-known urban sanitation systems and the existence of a form of municipal government.[58]
Others may define it more narrowly, but to me, PPC arbitrage basically involves setting up PPC ads (via Google AdWords or similar platform) and directing the traffic that results from ad clicks to a landing page or straight to an affiliate link (which many platforms don’t allow anymore).  The goal is obviously to earn more from the affiliate income than spent on the ad clicks.  You aren’t adding any value, but merely earning more from traffic than what it costs you to generate that traffic.
This is a venture that is growing rapidly. You can create videos in just about any area that you like — music, tutorials, opinions, comedy, movie reviews — anything you want . . . then put them on YouTube. You can then attach Google AdSense to the videos, which will overlay your videos with automatic ads. When viewers click on those ads, you will earn money from AdSense.
Dividends made sense 40 years ago as a relatively simple rule of thumb, but after all the work done by John Bogle with index investing, and academics with Monte Carlo sims and the 4% rule, dividend investing just isn’t the simplest, cleanest way to invest or receive passive income anymore. It’s actually significantly more risky compared to index investing, because dividend companies are a much smaller share of the total global economy compared to the broader indices.
If you have a spare bedroom, you can find a roommate or list the space on AirBnB for travelers. Having a roommate is the more passive of the two, as being an Airbnb host will require more work in the form of turning over the room between stays. This is a super painless way to earn $500 to $1,000 a month without much effort – you may even be able to cover your mortgage payment with this extra income!

An obvious example is over exposure to bank stocks, which have been excellent investments for over a century.  Though a foundation of most portfolios, bank stocks do involve more risk at certain stages of the economic cycle than many realise.  Being less exposed to bank shares in the last few months could have preserved some capital.  So, a more diversified approach can help mitigate some of these risks.