Thank you to Justin Lai for these helpful tips & tricks!
Standard selection
You are about to pick a tool
You have picked up a tool and are about to use it
n: Normal view
d: Dimension
spacebar: to drop selections (cursor with number)
esc: to drop tool
shift: to suppress help while sketching
shift + ?: brings up all shortcuts
Changes orientation of the part
Right click & hold, move move mouse around
Two-finger click & hold trackpad, move fingers around
Changes how much of the part fills up the space
Roll the scroll wheel
Two-finger swipe up & down trackpad
Changes location of part on screen
Click & hold scroll wheel, move mouse around
Click & hold 'control,' two-finger click & hold trackpad, move fingers around
Mouse-over item in the feature list to reveal the eye icon
Click the eye to hide, click eye again to show
*to clear up clutter: hide/collapse things you do not need
To save & exit sketch
To re-enter this screen: double-click "Sketch 1" in feature list
Insert new element
Create new Part Studio
Rename Part Studio
Create sketch on a default plane
Hide/collapse unnecessary items
Normal view
Draw reference (construction) lines as needed
For more sketching tips, check out this Onshape blog.