Brewed my first batch and followed the directions to a t for a 5 gal batch and got just under 4 gal of beer. I couldn't use the very bottom of the bucket because of yeast and sediment. Any tips for the next batch?
you will always loose some to fermentation, transferring, dry hopping, etc. you will notice on some recipes that they yield 5.25gal. this is too guarantee 5gal at bottling.
without knowing more about your process i can't give specific things to try.
Brewed my first batch and followed the directions to a t for a 5 gal batch and got just under 4 gal of beer. I couldn't use the very bottom of the bucket because of yeast and sediment. Any tips for the next batch?
The entire process of brewing beer consists of losses from boil off to trub loss to dead space, you need to account for these losses so you start with the right amount of water in the beginning minus these losses to achieve your final volume.
Sounds like a kit, which is fine, but the directions tend to rush things a bit. Another week or two in the fermenter will allow the yeast and trub to compact resulting in more beer in the bottles.