If you have very thin objects, your ribbon may struggle to wrap around the wrapper. To fix this, you can play around with the ribbon location and its width until it fits nicely on your wrapper.

For sure! All you need to do is append the "Gift Wrapper" collection from the Gift Wrapper blend file. Make sure that you set the "Origin Object" setting in both the Wrapper and Ribbon geometry nodes panel is set to the (parent)object that you want to wrap in your scene. 

There's a chance that if you import an object, it is not placed at the origin of the scene. This means that the wrapper and ribbon can't find your object. The fix is to either move your object to the scene center (world origin), or to set your object as the "Origin Object" in the wrapper and ribbon geometry node modifier panel.

If you want your wrapper to appear at the location of your object (instead of the origin of the Gift Wrapper blend file), make sure to set the Origin Object setting of both the Wrapper and Ribbon in their geometry node modifier panels to the object you want to wrap (or parent object in case of collections). That way, the wrapper and ribbon will be moved to and with that chosen object. 

As the bow is instanced on the top point of the ribbon, it can on very few occasions jump away from the mesh. If that happens, change the Ribbon Y or X Location just slightly until the bow is placed on top nicely.

There is a setting in the ribbon geometry node modifier panel called "Realize to apply". If you want to convert the ribbon to a mesh (by converting or by applying the modifier), set that setting to 1. This will realize the bow instance and include it.

If you have a detailed object that you are wrapping, your ribbon probably needs more resolution as well. So simply play around with the Ribbon length resolution and ribbon width resolution in the ribbon geometry node modifier panel. You can also change the ribbon distance to object to move it out from the mesh.

Due to the wrapping method and the UV unwrapping that happens afterward, the geometry can sometimes not be UV unwrapped properly. Don't worry though, there is a very easy fix. Change the Wrapper Size in the wrapper geometry node modifier settings just slightly until the material looks right!

In the wrapper geometry nodes object there is a setting called "Wrapper Size (Before Wrapping)". This is the size of the wrapper before it wraps around your objects. If your wrapper is too small, it will not cover your entire object. If you increase that size you will see that it wraps more and more until it completely wraps your objects.

In the Gift Wrapper collection, you'll find a collection called "Objects to Wrap". Place any objects or collections in there and that will add them to the gift wrapper. Remove objects from that collection to exclude them.