My hardest games are where the board is filled with terminal actions. When you have a board where 10 out of 10 actions are terminal actions, some of which are attack cards, or there is one card that has a plus card and plus action, but may not be the most appealing to chain with, I'm not sure what a good strategy is here.
It seems like it may be beneficial to go with a 2 or 3 to 1 coin to action, does that make sense?
A high money:action ratio is definitely required with an overabundance of terminals. What ratio is appropriate will depend on which of those terminals you decide to use and if/how you're being attacked. Generally it's better to err on the side of too much money; people aren't usually disappointed by a hand full of Silvers, and you won't bore your friends taking time to decide which 1 of 3 actions to play. A slightly augmented big money strategy is often very competitive in the absence of an engine.
If your hand will be small (due to, say, a discard attack and not much card draw available), you can risk having more actions because they odds of collisions are lower. In a >2 player game where you think Militia is likely to be played between almost every one of your turns, you could probably do nearly a 1:1 ratio of Militias and Silvers until you get to Golds. Games like this often end on piles, so getting an extra buy and starting early on Duchies is probably a good idea. (If you're discarding cards anyway, they might as well be points rather than money.) Also realize that in games with more than 2 people, joining in on attacks is less mandatory. If both other players are snapping up the Militias, you'll be better off letting them attack each other and instead getting a card that actually benefits you (e.g. Navigator).
On the other hand, if you are trashing or drawing a lot, you should be buying more money. If one of your terminals is Council Room, that means you're drawing 4 cards and hoping none of them are actions. Even if your terminal only draws 2 cards, if you've gotten rid of your Coppers, you need to be buying Silver and Gold to make sure your deck has enough money cards. "Doublejack" where the only non-money cards you buy are two Jack of All Trades is incredibly good because it trashes, draws, and helps you treasure-up all at once (not to mention it's extremely resilient against attacks). And you only need 2 Jacks to do it.
On boards like this, you will indeed want to buy mostly Silver and Gold, with no more than a few Actions.
How many Actions you buy will depend on the Actions. If your Actions draw you cards, you will usually want fewer of them. Smithy and Envoy in particular provide powerful increases to your buying power and help cycle your deck. A deck with nothing but a single Smithy or Envoy and treasure can be pretty powerful, even against fancy action chaining. But adding a second drawing card doesn't help much, because if you draw both together (likely, since each one draws cards) the second is a wasted card and you'll wish you had Silver instead. Library, Council Room, and Hunting Grounds similarly don't play very well with other actions in the absence of Villages.
On the other hand, if strong terminals that don't draw are available, you can probably afford two or three in your deck. These are less likely to collide and be wasted, because they don't increase your handsize. Shujaa cited Militia, which is an excellent example. Other candidates include Navigator and Jester.
If there are actions that offer +1 Action, consider them carefully along with your terminals. With terminals that draw, they can be risky. Drawing a Market with your Smithy is maddening. If your terminals don't draw, it's less of a risk. Also, if powerful chain drawing like Laboratory or Stables is available, make sure you know where your +Buy is coming from. It does you little good to have a $14 hand if you have only one buy.
Finally, I want to second shujaa's recommendation of Jack of All Trades, an important card on any board and a dynamite card in any deck that doesn't rely on heavy action chaining. Filling your deck with Silver, trashing Estates, and not losing handsize to do it is a powerful combination.
