In a nutshell: Generally speaking using liaisons when it’s not absolutely necessary makes you sound formal or even stiff or old-fashioned, so pretty much a who/whom situation.
But there are a few liaisons that are more-or-less universal (a good example, mentioned in a comment, would be “deux amis”). And others are never used (or “forbidden”) so that making them will come across either as a joke or as a clumsy attempt at sounding sophisticated when you’re not. So you cannot always pick and choose and even informal speech will have some.
The literature on the subject is vast and involves a lot of variables (phonology, syntax, sociolinguistics, frequencies, …). For an overview of syntactic contexts you could look at Bonami & al. (2014, §3.1.1) and the different studies cited therein.
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