Newbie w/liner and doubler questions

[dylan1984]

OK, with lotsa help from you ladies and some great mamas on DS, I think I'm kinda getting this thing down....prepping a stash of miscellaneous dipes (lotsa prefolds, several pockets, some AIOs I found cheap used, some covers, a fitted here or there, know what wet bags I want, got a diaper sprayer in line, got some wipe solution, got some wipes, know what I want more of etc) BUT I am having some issues with something: inserts and doublers.

First, what is the difference between the two?
2nd - I see many different kinds and some seem quite a bit more $$ than others - I think it seems to be the hemp and bamboo are more
3rd - sizing - is this really important? can they not just be folded up until baby is bigger
4th - is it not WAAAY cheaper to make my own - I'm no fancy seamstress, but I could manage to sew two layers of fleece together - does it need to be a special stitch or anything? I wouldnt' think so as wouldn't rough edges be softened since they are going into a pocket?
5th - just would love general opinions on different materials - should I have a variety of say MF, bamboo, help, flannel, as they all have different desireable properties?
6th - if you think they are way cheaper to make, and easy for a sewing dummy who does however, have a sewing machine, do you have some simple instructions?

TIA :

[Juliacat]

Liners are mostly for helping with cleanup, doublers are mostly for adding absorbency.

I didn't use them much--generally one diaper was enough for daytime and two was fine for night when bulk didn't matter.

[dylan1984]

OOPS! Just realized I wrote liner when I meant insert - is there a difference between an insert and a doubler?

[RGsMom]

Not really too much difference. An Insert would just mean you are inserting it in a pocket and a doubler you could double up your insert or you could add a doubler on top. Which you wouldn't want to put any MF for the top layer, but Hemp, Cotton, and Bamboo, and Fleece are generally fine. Hemp is more expensive, but it also absorbs more which is nice. That is one reason I like the Super Do Inserts for night time because they are MF for quick absorbency and Hemp for greater absorbency. Does this make sense?