Rigging and Clothing

Ok so i have a problem.

I have my human mesh, i have it rigged and working fine, now my armour/clothing is all seperate pieces, ive parented the shinguards, the forarms, the upper arm etc bet im stuck on the chest and leg armour.

How do i go about parenting them to the rig, if i parent the legs to 1 leg then theres an obvious flaw, if i parent to 2 they only work when the latter leg moves.

Ive tried going down the weight paint route but i cant seem to select the bone, then the pants and weight paint them. I tried parenting the pants to the mesh and they still dont move.

Similar problem with the chest, if i rotate the top half of the bodythe chest rotates through the body.

How do you guys solve this? Any tutorials would be helpful.

Ok think i figured it out at least some of it to a beginners degree, joined the items to the main body and then was able to weight paint them. Still some wierd shapes happening when moving the limbs but it will do for what i need it for. Now just need to work on the boots.

PS: If anyone has a good tip for skinning a full chest piece to a rig, lemme know, this is my first time doing anything like this so all the help is welcome.