I'm a corporate recruiter. I used to be a "headhunter" and worked in search. You can make a LOT of $$ depending on industry (ie IT, Finance, healthcare, etc).
No start-up capital needed. Manage your own time, work from home. Need phone/internet connection. DONE.
Business development via LinkedIn, associations/events/networking.
20-30% fee of first year's salary or if you do contract, make maybe $3-10/hr margin per person placed (so - if they work 40 hours, you make $400/week - contracts is a better gig actually than perm placement having done both myself).
You don't need experience - you have to be good with people, they have to like you, it's a lot of sales. You have to be well organized, good at sales/have energy. Be diligent and consistent. Work hard but you have the luxury of managing your own time. It's not as "easy" as some people think it is but it's a really good self employment opportunity because it's effort based - anyone can do it. It's an AWESOME biz model. You also feel good because people you get a job for think you are God and your clients will be happy too

Win-win on the most meaningful scale. Corporate recruiting is less money but more stability and you can still do 6 figures if 10+ years of experience depending on industry. My first year in search with no experience at age 24 I made $150k. No joke. Never worked more than 40 hours if that.
To PP - I recruit salespeople and yes depending on the industry and company, you can absolutely have an awesome sales gig that is a work/life balance and make $$$. Totally. Everything depends on who you work for, what your boss is like, how they structure comp and whether you are new biz dev, account managing, or responsible for combo. Outside sales always makes their own schedule. Inside sales is straight 40 hrs/week and you can make more than $60k if you are good frequently.