I sometimes notice players(including myself) not play well. This is because they are not focused. These questions should help you stay focused on winning. Let's suppose we have a kingdom with junk dealer, margrave, highway, village and some irrelevant cards.
The first question we should ask ourselves is what is the most effective way of winning?
Since this board has no alt-vp cards we need to get provinces to score points or end the game on piles. This leads us to ask:
What do we want our deck to look like before we start greening?
We want our deck to look something like this. 1 junk dealer,5 highways(more is always better but in a mirror you will probably get 5, 3 margraves(To draw deck, attack and give + buy), one village per margrave you get.
How do we get there?
Because most of our engine pieces are costing 5 and there are no kingdom cards that help us hit 5 better than silver we should open double silver. If we get lucky enough to get 5/2 we should pick up a junk dealer. Junk dealer helps us trash which is a good thing.
Why do we want to trash?
We want to trash because when we draw a card we want to draw a card that helps us have a better turn. If that junk card had not been in your deck you would have drawn a better card. Suppose I drew a hand of 3 coppers and a margrave and a estate. Now let's suppose that I had trashed all those estates and coppers. I would have drawn many more villages/draw cards/highways if those junk cards wouldn't have been there.
On 4-3$ hands you should get villages because silvers do not help you that much and will clog your hands up eventually(Do not be afraid to trash your starting silvers)
After we get two junk dealers we should think about how our deck is doing.
If we have several villages but have not trashed very many cards it is probably time for a highway.
If not pick up a margrave.
How do we win the key splits?
In this case highways are the key split because that will be our main source of economy.
There are many ways to try to do this. In this board you really have two options
1)Buy highways earlier than your opponent
2)Get +buy cards two buy two(or more) highways in a turn.
Skip forward a few turns...
You and your opponents deck should look something like this:
5 highways, two junk dealers, 5 dollars of real economy(non-highways), 3 stop cards, 2 margraves, 2-3 villages.
How do you want to plan the endgame?
Given that you do not have enough economy to double province(provinces cost 3) but can draw your deck every turn(almost)You have a few options
1)Go straight for green
2)Get cards that help you control piles (Margrave helps give you + buy)
3)Get enough economy to double province (single gold should do the trick)
After the game is over you should ask yourself:
Why did I win/lose And What did I do different than my opponent
This is a tough question. Many times you can do more than one option at one time.