First off I don't use the strings that come with Studio One 5, there are a ton of great libraries using their own plugins or Kontakt (if you're looking at doing more orchestral stuff I'd recommend looking at Spitfire BBCSO Discover it's $50 or free if you take a survey and while it's not really versatile, it comes with a lot more than just strings and could be a great starting point if you're interested in orchestral ****. If you're not, don't bother.) Anyway, usually to make strings sound more realistic you fix the timing as most have a bit latency, so drag the notes ahead in the S1 editor to sync up their timing with everything else, then humanize the timing a small amount. You would also adjust the velocity on the staccatos, pizzicatos... (your shorts) and the expression usually cc1, but does vary{ could be cc7, cc11, or something else], for longs and legato. Last add a good reverb on them as a group to get them to bind together a little better (Depending on what you are mixing the strings with/for it's pretty common to use both an Convolution reverb and an Algorithmic reverb. One to group your intsruments together and the other to match the space your mixing into (the convo for space and the algo for tail). I hope this helps a bit. Good luck and have fun!