Ha, so I need to say up front that YMMV, and I'm probably not the model you'd end up settling on if you're a sane person.. but I'll give you a solid overview of my deal.
I typically charge $100-$150 an hour, as well as fixed fee when appropriate -- depends on the scope of project, how many (repeating) hours they're willing to toss me, etc. I'll accept lower rates for more hours / longer projects. I'll charge higher rates for emergencies and really off the wall stuff.
My skillset is highly-experienced generalist (25+ years professional experience) in a wide variety of areas, to the extent that I break the ice with "I do computer" if anybody asks (to make them laugh and also get a feel for what they want to know / what areas I should talk about). Most clients are looking for incredibly specific things, so they're not shopping for a generalist, just somebody who can accomplish their (usually very) particular task. That gets your foot in the door, and they'll often just keep bringing you more things to do for them since the pipeline is so short.
My actual, tangible experience ranges from front end and back end development (in many languages / stacks / platforms), native mobile development (Swift / Kotlin / React Native), API development, dev ops, database architecture and administration, UX/UI, e-commerce, graphic design (identity / branding, web/digital, print, apparel, packaging), 3D / CAD modeling, sound and audio design, etc.
I can conceive, design, implement, launch and administer an entire concept from end to end (although, one-man bands are rarely the right solution, very little of significance in this world actually gets done by a single person in a vacuum)
Currently, my clients range from:
- agency work (staff-aug front end development on specific websites for their clients)
- graphic design (digital assets + apparel + miscellaneous for record labels)
- building and/or managing websites for small businesses + music industry (Squarespace + Shopify + Wordpress, including custom admin panels, tools, and integrations into their day to day business + 3rd party SaaS tools)
- built, maintaining and extending a couple of large, custom websites in the university and auto industry spaces (ex. one is a platform that external vendors use to enter and move purchase orders around, that kind of thing)
I can usually slot into most anything and produce quickly, just because I've ended up working on something similar in the past.
I'm based in the Midwest (USA) and am a solo practitioner -- and, FWIW, in my early 40's with a wife and kid; important to note, since it's easy to dismiss all of this as youthful foolishness -- I don't operate like some contractors do, who win the work and manage projects while farming out to 1099 contractors to actually do the work. As I mentioned in my original post, I like the small business / service model, ideally working with clients to whom I'm already a known quantity (from previous gigs, word of mouth, or working together in the same organization in the past) because it lends itself well to the "small retainer" concept -- these types of businesses typically just need prompt, competent help when fires flare up. Some weeks, months even, you never hear from them, so if you can have a bunch of small retainers (whatever, 4h or 8h a month) running side by side, and you're always around to help them out (you're "their guy"), it's a drop in the bucket for them to pay that out over the course of a year rather than have an emergency and spend 10x in time and money attempting to find and engage with somebody who is willing to help them when they need it (or god forbid a small agency, with a 2-month client onboarding, 12-month-minimum retainer, 6-person team to manage your requests)
Get enough of that lined up and it creates a predictable "base" income stream, and then if you can find a series of more transient clients that come and go (3 months at 30 hours a week before they disappear for a while, then you can give a different one 20-30 hours a week until that craps out, etc) that's more of the variable income that layers on top.
Note that I don't charge beyond the small retainer unless they're bringing me enough requests consistently to warrant it -- as in, if 3 months go by and it's been just little ones-and-twos updates, when big shit hits the fan I just take care of the problem regardless of how long it takes, and life goes on. For the strict hours-based clients, I charge whatever they're asking me to do. More work? More hours. For fixed fee, I feel like that's pretty much my fault if it spirals out of control, and I just suck it up and eat the loss, especially if there's no likely probability of getting them to agree to increase the fixed fee.
All of this means that, of course, some weeks are insane, while others are dead. I don't actually do very much weekend work, but I'm always available to communicate with (and willing to jump in) when it's warranted. Some industries like music/entertainment are 24/7, so tour websites, digital assets, campaigns surrounding releases, sometimes that stuff needs immediate attention, and I work with people and teams in timezones ranging from LA to London (and in-between). I've even got a client based both in Germany and Kenya as well, so you can imagine the asynchronous, out-of-time communication that sometimes goes on.
To fully answer your question about time management, now that I've got a solid workload set up, 99% of my time is billable hours. I have to hustle (biz dev) if/when the work starts to dissipate, I have some weekly and monthly obligations for time reporting and invoicing, but generally it's just solving problems and building things most days of most weeks of the year (this is by design). But again, I'm just one dude, doing this by myself -- if I was subcontracting, hunting for (and responding to) RFPs, doing cold client outreach, that would really eat into my availability and reduce profitability. I also occasionally get brought something that requires a POV / MVP / formal pitch, and those can waste quite a bit of time if I end up not getting the project. That's just how it goes sometimes.
It's also important to point out that my actual scenario is impossible to reproduce -- you only know who you know, I tend to trade off of my personality and charisma, I really love what I do, I have a very high tolerance for risk, I'm self-motivated and disgustingly optimistic (read: completely delusional), and ultimately I'm just out here trying to make cool shit with cool people, help people navigate the minefield of modern technology, and most importantly, have a lot of fun doing it.
I also am friends with people who approach this whole thing from the complete opposite direction -- where I'm flying by the seat of my pants and just stoked to have opportunities to get in there and get my hands dirty, they're far more analytical about it as a real business, with boundaries, rather than purely as an undeniable passion and vocation.
Anyways, good luck on your journey if you decide to take the leap!