The main difference is that at the end of the day I try to just stop when I have "enough" hours, since I don't get paid for overtime like I would as a contractor.
To the original topic: roughly 40% of my week is wasted on pointless meetings or inter-meeting dead time. The other time is roughly equally split between useful meetings, actual work, and admin or training tasks.
The issue with the pointless meetings is that they are generally a series, where one 10-minute slot out of every four one-hour meetings is genuinely useful - but you don't know in advance when that slot will occur. The other kind of pointless meetings generally involve customers who are unprepared.
That's double billing and afaik illegal, you can not (and rightly so) bill your customer twice for the same time.
Consulting is a relationship business. You’ll make way more money focusing on the people rather than the work. You can cover up sloppy execution with a good relationship, but stellar execution won’t save a project where you fuck up the client relationship.
Send me a text a minute after I've finished working for the day to check on the status and it takes me a minute to read and reply? No problem, I just billed the client for 15 minutes. Takes them 15 minutes to come up with and send a response that I need to respond to ASAP? Another 15 minutes billed. Want me to spend 3 minutes at the end of the day itemizing the bill? Perfect, that's another 15 minutes billed!
The more granular the itemizing, the more opportunity to shove the minimum billable increment in their face. Called me for a two minute chat while I'm in the zone on their project? Gotta itemize it! 15 minutes billed and I restart the work (out of the zone) at the top of the next interval.