you need to read the batting packages...there are ones that say---good for tied quilts----there are ones that say must be quilted every 2"-4"...those are NOT GOOD for tied quilts- that is when you get balled up batting in a washed quilt-
some batts are simply not made for tied quilts- the ones that are say so.
when you tie a quilt there should be a tie every 4"-(about) the way to distribute them is in a grid- and every where you place your fist should touch a tie-top, bottom, left, right....in squares.
when our group gets together to tie quilts we put them on a frame- bottom, batting, top, smoothed taut but not stretched. then we work together to pin basted it- around the edges-anywhere we think needs a bit of (hold) then we go about getting it tied.