There are a couple of options that can catch you out in Illustrator; have you ever had the problem where you scale up an object but the strokes don't get any bigger? Or vice versa where you scale down your object but the strokes stay huge leaving your design all out of proportion and looking just plain ugly?!
If you are experiencing this, you'll be glad to know there is a quick and simple fix right in the preferences panel…
So just to reiterate, you have an object such as the smiley face above, but when you go to scale it up or down the strokes and/or effects do not, leaving it all out of proportion.
The fix to this problem is a simple four clicks:
Go to Edit > Preferences > General or press Ctrl / Cmd + K.
In the preferences window simply click the 'Scale Strokes and Effects' checkbox.
Click OK, and as by magic your strokes now scale in proportion to the rest of your design! Easy.
More Vector Graphics: 
