Make up for pack lack of sternum strap

[Rgarner]

I don't sew and have no access to a seamstress/seamster. Is there some other way to crosslink the shoulder straps of a backpack? Also it would be good to have some kind of belt at the bottom.

 

[PitCarver]

No need to cross the straps, there's plenty of options on all the sales sites for straps...

https://a.aliexpress.com/_mPoW30z

For one.
You only need a waist belt when you're carrying heavier loads and you need to more evenly distribute the weight lower on your body.