let me give a sample of practical deliberation. I will use an example from von Wright (from memory, so apologies for errors in quotation).
I want the hut to be habitable.
The hut will not be habitable unless I heat it.
Therefore, I ought to heat the hut.
The first premise is the end to be satisfied. Such ends are the starting point of practical deliberation. It does not take a philosopher to determine what ends I have; so long as I can recognize that I desire something, I can deliberate how to achieve it.
The second premise asserts that there is a means to my end (a necessary means, in this case, the simplest sort of practical syllogism). This is, in essence, an assertion of a causal relation: doing such-and-such would realize my end (i.e., cause it to be true). Obviously, such causal relations can be found scientifically, though arguably the bulk of such assertions are found by non-scientific, informal observation. The former are, of course, better justified.
The conclusion asserts that a certain action must follow, or I will be practically irrational in this instance. So long as I aim to make the hut habitable, I must do what is necessary to make it so or else I am irrational.
So, a simple example of deriving an ought statement (of a non-moral sort) using facts of the world about us. (Many ought statements in morality also make use of facts of the world, of course, but this example should suffice for now.)