Efficiency makes all the difference in making a profit. Even if you get a better price with your bid, and take more time to do the job, you may not fair as well as another crew that completed the job at at a lower price but in less time.
Using all the tools to speed the job along is the key. Not making trips to the supply house all day helps, having enough ladders is the biggest help in residental I've ever found, dragging ladders around just kills me, we set up six or seven and go up and come down where we need to, not where we left the ladder. Just having a plan and sticking to it, get done what you have to that day, an extra half hour today might save two tomorrow by not having to get out and put up tools you only need for a half hour more, the next day you get them out and put them up again for nothing. Wire spools have save us plenty the 1000', we buy range cable, 10/3 all on spools, we never run out and never pull short, mistakes kill your time. A trailer full of stuff you can't find is useless to, get a hour on sunday evening to be prepare to restock first thing AM Monday, save you a half a day easy.
Sorry to sound like a teacher but the couple of guys I worked for the most were speed freaks, gotta make time, to make money, the better we worked, the more we made. I've had to teach my newest guy this from scratch, it's nice to have a clean slate,like molding a piece of fresh clay. Time is money don't waste either and you'll be fine.