If it looks funky - toss it.
If it has an Expiration
date and it is past that - toss it.
If it has a Best By
date and it's 3 months or more past that and has been opened - toss it.
If it has a Sell By
date and it's past that - and has been opened for 3 months or more - toss it.
If it's been opened and you haven't used it in the past 6 months (even if within the Expiration, Best By or Sell By dates) - I would toss it.
If it's just a "dab" and you rarely use it ... use it up or toss it.
If it contains fat (oil) and is over a year old - toss it.
That should get you down to one shelf in the refrigerator door.