Hey there! Girl with short lashes here! I typically don't wear mascara but when I do, I understand not having anything to make lashes look thick enough and something that wouldn't smudge (I always forget I'm wearing mascara, rub my eyes or cry or something, and then have streaks or smudges of black everywhere on my hands and face). I personally would suggest Maybelline New York Great Lash Waterproof Mascara. It's good for volume on your lashes but also great for a non-smudgy look. It's pretty cheap and you can typically find it at your regular store like WalMart or Target or something but it works well.
Another thing that has worked well for me is Avon Mistake Proof Mascara and similar products with the eraser on it. I'm not very coordinated when it comes to putting on mascara (I've stabbed my eyes before...) so this not only has really helped me when I was first starting out with wearing mascara but also when I had smudges later on, I was able to just clean it out really easily. But these rarely smudged from my personal experience so if you're like me and aren't very handy with mascara, then you could try these kinds out.
Anyway, if you want to make your lashes look longer, just remember to use eye curlers before you apply mascara.
