Starting things off:

-->Dine at the Round Table in the nude. (OK, just the base garb.)

Taking off your clothes makes the stamina gain show up on your base (plus house-based) stamina. Putting your clothes back on after dining gains you up to an extra 20 points with the Meidi set, 110 extra points with the saint's garb. And not just at the Round Table. Whenever you are eating comestibles to regain Stamina, strip down first, whether you are fishing or mining or logging or whatever. Dining au naturel is just better.

It's also best to sit in your massage chair naked, too. Don't worry. Mint won't know...

[EDIT]
Just noticed. Been at GOG for more than 13 years, slightly over 1000 games, still listed as "New User"
[/EDIT]

Pick Up Poop

At least until you get your first lettuce seed. You need it for the early trap box, which has a major game impact, and it's otherwise not available until you complete Emily's mission. I think it still makes sense to plant a wheat seed to get the mission completed quicker, but I don't know that it is essential.

To that end, picking up a few extra fertilizer from Sophie as you can afford it is a good idea.

[EDIT]
Don't think it used to be this way, but as of the current version of the game, lettuce seeds are available at the beginning of game. I suspect the poop advice no longer applies. Even a base salmon nets enough that stamina-wise, you are better off buying lettuce seeds than the RNG finding them for you. So picking up poop in early game makes sense only insofar as you need it to make planter boxes, 5-6 of which are probably a great plenty until you can afford the second land purchase.

I don't think it probably makes sense to ever make fertilizer with it. Mucus is too useful to waste. ("I'll take, "Things I Never Thought I Would Say" for $1000, Alex.")
[/EDIT]

If you are using the Day 2 massage chair start, it's often best to hold off on fixing your house for a day or two. It takes under a half hour of the day to recover that few missing stamina, (depending on how many levels you gain on Day 2, it probably takes under 15 minutes of your day) and the 36 wood can be better utilized running furnaces. (If you are totally flogging the Roping mini-game, there's never a point to the repairs -- you only need a max of around 30 milk (6 or so plays of the mini-game if you just rope whatever comes your way, rather than waiting for only milk producers) to top you up in the morning, no matter what level you are. But that gets old fast.)

That half hour or so does add up, though, so at a guess, you should probably do the repairs after you pick up the reward for the Amber Island bridge on Thursday. You can take a bit of a breather there, anyway. So long as you have a couple of Civil Furnaces ready by the time you bring iron home on Friday, all is well. Heck, might even be worth buying iron from Total Tools Friday morning to get a jump start on your pick. [EDIT] Turns out it is, so long as you have at least two Civil Furnaces ready to make iron. Looks like one Civil Furnace is about break even. If you don't, or can't make at least one as soon as you get to your workshop after doing your morning loop, it's not. [/EDIT]

Now, granted, some of this only really applies if you are seeking the same kinds of personal goals I am, which is minimizing time to complete reasonable relationship points, finishing research as soon as possible, (though I have not yet been able to drop off 15 discs on Tuesday, I usually manage 5, and, if not, definitely the 15 on Wednesday), mount as soon as possible (I've managed the 11th of Spring, but I think it can be done by the 10th without sacrificing my other goals if you can get 2 Old Parts on Tuesday morning), minimizing game time to accomplish main mission (including Ack by the 18th, completing Bassaino Lift on the first Fishing Day, etc.), mini-drill by the end of Spring, taking all secondary missions, etc., that kind of thing.

Incidentally, it's kind of fun to be mucking around in the Collapsed Wasteland 5 days before you are allowed to be there. ;)

Django's Game Room

Underrated. If you can ace the dart game (or better yet, slots, but I just can't get the hang of it) you can sell Seafood Noodles at a profit -- 30 Gols gets you 1 Seafood Noodles, which sells for 74 Gols, and time stops while playing darts, so you aren't out anything more than what it took to walk across the restaurant there and back. Alternatively, it is also the lowest cost "renewable" gift I know of for Arlo, Nora and Phyllis. Yes, you will find a better choice for Phyllis later, but if you want, all three can be at 11 relationship points on Tuesday without leaving Peach Plaza.

Save a Trip Home With Your First Furnace

Once you build the furnace for your builder test, put it down in your workshop, start it doing something (I recommend bronze from ore you bought from Total Tools), pick it up with "F" and go talk to Presley. As soon as you talk to him, it will teleport to wherever in your workshop you had placed it, and you've received furnace credit for the time you were carrying it.

May not seem like a big deal, but that just saved you at least 20 minutes of game time, which can easily make the difference between getting 5 discs to the Research Center before they close on Tuesday or 15 discs before they close on Wednesday. Which would delay iron by a day, which has huge repercussions in terms of mining/logging, at the very least...