PE2: Using a duplicate or a new layer?

[Rich10]

Another newbie question concerning PE2: I am a bit confused as to when you use a duplicate of the background layer or a new layer. For example, if I want to sharpen, blur or tint on a new layer, when and why would I choose to do these operations or other operations on a duplicate (of the background) layer or on a new layer?
Thanks.
Richard Hirschman

[Doug Nelson]

It's just my opinion, but you should always try to preserve your background layer as much and as often as possible. So, if there's any way to do an operation without affecting your bg layer, that's the best way to go.

[Rich10]

Doug,
Thanks. Still confused a bit though as to which operations require a new layer and which require a duplicate layer. I guess if pixels are required, such as for blur or sharpen, then a duplicate layer is necessary instead of a new transparent layer. But how about tinting? Shouldn't you get the same effect if you tint a duplicate layer as you would with a using the tint on a new transparent layer? I tried both and the results seem different but I don't know why.
Thanks again.
Richard