A
"sobre" is usually an
"envelope" but it can also be a
"packet", as in those little "sugar packets" they use in the cafeterias. Those are
"sobres de azúcar".
I wouldn't translate
"bag" and
"pouch" as
"paquete".
"Paquete" is
"package" or
"parcel" depending upon which size of the Atlantic you're at, or
"pack" as in "a
pack of cigarettes"
- (un
paquete de cigarrillos)
"Bags" and
"pouches" are
"bolsas". When they're small we just say
"bolsitas".
I believe a
"pouch", depending on its size and also the usage, can be a
"talego", at least in my country.