We had luck with laying my son down on the diaper changing table and then gently pinching his cheeks together to help funnel it down. (this sounds really weird in writing) I hope it makes sense.
Anything you can get in flavors
Honestly, I use a medicine dropper, hold him down and kind of funnel in it.
It sounds horrible, but I just prefer to get it done and over with and know he got the correct dosage in about 20 seconds.