Welcome To Motherload! Here are some tips for starters!
Tip 1: Dig Straight Down (But Only Branch Out For Expensive Resourses) So That You Can Fly Straight Up At The First Sign Of Low Fuel.
Tip 2: Dig Near The Gas Station So You Don't Accidentally Explode From Fuel Loss when rushing and that you'll be closer to it.
Tip 3: Buy A Better Gas Tank As Soon As Possible. So you don't have less time to mine gems/rush to fuel station.
Tip 4: Never EVER Pickup Ironium!!! It is worthless and will waste your cargo bay space.
Tip 5: When Very Deep Don't Dig Dirt Blocks Around Where You First Find Emarald And Below Or You Will Explode. There Is An In-Game Warning About This The First Time You Reach It.
This is about it.