Add a new layer named "ground2"
Set the second brown as your foreground color and
click on your paintbrush tool and using the settings from before,
paint a few lines on your shape

Now go to 
Effects>Blur>Gaussian Blur>4

Then Make your Pumpkin and Stem Layers invisible and merge all visible layers
Rename this layer ground

Then go to Layers>Arrange>Send to Bottom

Looking good!  We are now seeing the pumpkin! Now it is time to add some leaves and vines!

Add a new layer named "leaf" and open your pumpkinleaf.sel file
Click on the first green color and floodfill the selection.

Add a new layer named "leaf2"
Set the second green as your foreground color and
click on your paintbrush tool and using the settings from before,
paint a few lines on your shape..do the same thing with the third green color

Now go to 
Effects>Blur>Gaussian Blur>4

Then Make your Pumpkin, Stem and ground Layers invisible and merge all visible layers
Rename this layer leaf
 

On your layer pallet, rick click on your leaf layer and chose Duplicate

With the copy of leaf layer active go to
Image>Mirror
then
Image>Rotate>and use the following settings

Now move this layer between your stem and ground layer

Then adjust the image so that it is behind your stem

Set the first green color as your foreground and click on your paintbrush tool with the following settings

And a new layer named Vine and move it so it is just above your ground layer
Now draw yourself some vines on either side of your pumpkin

Change your foreground color to the second green and staying on the same layer, draw a few small leaves on your vine

Wow...that is one nice looking pumpkin we've got there! LOL!  Now it is time to add some shadowing!

Add a new layer called Shadow and move it just above your ground layer
Change your foreground color to a dark grey..I chose #404040

Now, using the settings from before, use your paintbrush tool to add a
bit of color just outlining your pumpkin at the base

Now go to 
Effects>Blur>Gaussian Blur>4

Add a new layer called Shadow2 and move it just below your leaf layer

Now, using the settings from before, use your paintbrush tool to add a
bit of color just outlining the bottom of your leaf

Now go to 
Effects>Blur>Gaussian Blur>4
 

Add a new layer called Shadow3 and move it just above your stem layer

Now, using the settings from before, use your paintbrush tool to add a
bit of color between the top of the pumpkin and your stem

Now go to 
Effects>Blur>Gaussian Blur>4

Now merge visible and your done!