Scroll of Jumping (50gp to purchase, half that to craft, available under Adventuring Gear in PHB): Seems like most PCs that can cast spells, particularly at lower levels, will want this as an emergency escape button. The spell is a bonus action to cast (cast it on yourself or someone you touch), and lets you jump 30 feet for 10 feet of your movement speed expended and lasts for 1 minute.
So lets assume your PC, with 30 feet of movement normally, is in trouble. You got caught next to a baddie and need to withdraw but you're worried if you just disengage and move 30 feet the baddie will just catch right back up to you with its movement of 30 feet. This spell scroll can help.
You disengage and then can jump 30 feet expending 10 feet of your movement speed, and you still have 20 feet of movement left which you can use before or after the jump. It doesn't specify a long jump or high jump so I am unsure how this works with the normal jumping rules (you usually wouldn't want to jump 30 feet up unless your DM allows a Dex check to catch or land on whatever you were aiming for, because gravity). Regardless, if it uses a long jump (unclear in the wording) you just move 10 or 20 feet first then jump the 30 feet and use your remaining movement if you have any after the jump. You've moved 50 feet total with no opportunity attacks.
And now it lasts 9 more rounds.