I disagree with this.
The better the sample library, the more intuitive it should be. I define a "mediocre" sample library as one that is incapable of playing a melody authentic to the rhythmic vitality of that instrument within a single patch.
Allow me to offer a somewhat different opinion here:
You cannot "get around" mediocre samples if realism is your goal for the simple fact that if you don't have a sample of something, your virtual instrument cannot play it. You can try to "fake" something by manipulating the sounds, but that almost always sounds obvious. So it's best to just write to the samples' limited ability.
A good sample library will feature all standard articulations for the instrument, most importantly notes of differing lengths (Cinesamples is great at this), and you can do it all within one instance of Kontakt or whatever. East West Symphonic Orchestra fails on this account. It doesn't have any meaningful variation in short notes and it's a nightmare to use. You'll spend hours making it play the line you want, likely across several patches for one instrument, only to realize that a better library could've done it in a matter of minutes. So much "orchestra" music now is just "chord with left hand, melody with right" and banking on the fact that the lines have "true legato" as being "realistic" even though no orchestra plays exclusively legato through every phrase. Symphobia is a textbook case of such a "mediocre" library.
If it takes you hours and hours to craft a believable phrase, and even then it ends with a mixed result, it's a sure sign the sample library is garbage. And take it from me, a guy who spent a lot of money and time on this in recent years: A lot of "budget" libraries really suck.
It's not the advice anyone wants to hear, but the reality is, if you're serious about making realistic mockups, there are no "tricks" anyone is going to be able to give you — outside of learning more about orchestration of course — but it is inevitable that you need more capable samples eventually.