If u get them done professionally tell them thats what u want because they can do that my friend has had it done before. If there clip ins you can but it's a little more diffcult you have to place them correctly to get your hair to look thicker and not bulky because of the clips
I dont have extensions yet I just have long hair anyway, and if I out extensions in aswell I was hoping it would make my hair thicker
If you have thick hair it would look thicker and full of volume. If you have very thin hair it could look just thick and casual.
No but you can make your extensions look thicker. This website tells you how to do it :
Yes you can. I do them all the time for my friend who has fine hair.
I suppose u cud if u cut them to the length of ur own hair