Decisions
All life is a matter of taking decisions. We make decisions on a daily basis. There are big decisions which we take every now and then. Little harmless decisions are made several times a day. Decisions are made in the present for the future.

From an economic point of view decision making can be modelled as follows:
1. Either-Or-Decisions:Either Or Decisions have to be made because we cannot do two things at a time when there is a choice. in addition since resources and time are available in limited supply (Scarcity). See also the importance of implicit and explicit costs in decision making or how to make decisions when time is a factor.

2. How-Much-Decisions:This compares the benefit of doing a little bit more of some activity with the benefit of doing a little bit less of that activity (marginal cost)

3. When-Decisions
In cases where time is a factor

Sources
1. Eonomics Krugman, Wells, Graddy
Oxford University Press 2008

Linguistically decisions can be made:
Grammatically:
1. Instant/spontaneous decisions or when we make promises: Will

I am hungry - I'll get a sandwich.

I am cold - I'll get a pullover.

2. Planned decisions going to

I am going to see a film this evening

3. Decisions already made or arranged for (agreement) Present Continuous

We are moving house next month.

Lexically with the infinitive
Decisions can be made lexically as a substitute:

We plan to build a house
We intend to think it over

Collocations and other ways of expression
Make/take a decision
Make a crucial decision
Decide
Make up your mind