Considering their options

1. When you ask for a job.
　You: I want you to take this package to my desk.
　The other party: I need to send you the contract first...

2. When you are asked for advice on which is better.
　You: 1 is better.
　The other party: Then the customer told me that 2 is better...

Have you ever had a problem with being told in a definitive manner?
If you think the opposite or the situation has changed, the other party will not be able to reply and you will have trouble resolving the situation.

Solution

The fact that the other person is troubled by the definitive way of speaking shows that expanding the options makes it easier for the other person.
But, on the other hand, if there are too many options, as in the following, the person will be even more troubled, saying, "I have to think about what is being said, on top of what I have to do first...".

1. When asking for a job
   You: Carry the stuff over there.
   The other party: Which package do you want me to carry and where...?

2. When you are asked which is better.
   You: Either is fine.
   The other party: I would like to choose the one that is a little better...

the middle is better, and the optimal answer is to "choose words that limit your options (what you will ultimately do) and can be adapted if the situation changes," which is a way of speaking that is less likely to get the other person in trouble.

This point alone will leave you wondering how you should speak, but it is possible to make such a statement by adding a little negation to your own statement.

Specific examples

1. When asking for a job
   You: Can you carry this package to my desk? I can do it anytime as long as it is done by the end of this week.
   The other person: I don't have to deal with the dilemma of what you asked me to do earlier.

2. When you are asked which is better.
   You: I'm one, but I'm pretty confused.
   The other party: It seems to me that what I'm thinking is not a mistake either.

With a little negation like this, you can limit your options and feel less responsible if the other party has to choose another.