From Care2.com, "Getting Medicine Into Pets Effectively But Kindly."
See how the nice lady in the picture on the website is giving those meds? Don't do that.
Instead, come from BEHIND your pet's head with the dropper bottle. If he or she sees you coming from the front, it's easy to dodge, but if you face your pet away from you, point his or her head straight up, and bring the medication up from behind, you can often have the drops administered before your pet even notices it's happening.
The advice about not grinding up the medication is spot-on, and I might even extend that to cutting the medication in small pieces, too; some oral medications are exceedingly bitter-tasting, and leaving them in one piece limits the ability of that bitter taste to spread through the treat or food or whatever you're using to hide the medication.
The point about "chasing" oral medications with a syringe full of water is absolutely right, too. We're always happy to supply you with a syringe that's perfect for this purpose if you ask.
One very important consideration when administering liquid medications that I don't think the article really covers- DON'T point the tip of the syringe directly toward the back of your pet's throat. This can result in your pet inhaling the liquid into his or her lungs, potentially causing all sorts of problems. Instead, make sure the syringe is perpendicular to your pet's throat, which will allow him or her to swallow the medication safely as you give a little bit of liquid at a time.