Pack Up

I like choices and it is for that reason it takes me forever to pack.  How do I know today what I might want to wear three days from now.  Such a predicament.  Not to mention what will the weather be like.  Last time I traveled I planned for warmish weather and it snowed.  So I'm a bit gun shy.  So over packing works best for me because I just never know what season I'll be in when the plane lands!