As far as I know, only certain bags have been replicated: (I've included links to show the bags I'm talking about. This is not to say that the links are real or fake, just to let you put an image to the name)

• White Ghost Glow Mickey
• Loki Cosplay (Classic & Avengers Armor & President Loki)
• Thor Cosplay (Ragnarok)
• Disney Parks Halloween Snacks (Link)
• Star Wars Grogu in Ship (Grogu)
• Minnie MMA Teacups (this fake just popped up this year - LF Badge doesn't say Disney Parks, just Disney)

Some easy give aways would require you to have a little background knowledge or an image of the original to compare it to:

• Do the Loungefly badges match up? (Disney vs. Disney Parks/ Metal vs. Leather Tag)
• Are certain parts of the bag supposed to be appliqué (Sew on pieces of leather) and appear to be "printed" on instead?
• Coloring of material. Texture of material/appliqué. Placement of appliqué or prints.

You can google "Loungefly Fakes" and there will be YouTube videos.