Lay better eggs in what way? What trouble are you having with the eggs? Are you having shell quality issues? What are you currently feeding them? Hens should be on a layer pellet feed and it's never a bad idea to also offer then oyster shell free choice.
X2 @Pyxis ''s post...also, what breed (s), what ages, what are you currently feeding? Are you wanting to increase the number of eggs (how many per day are you getting now from how many birds)?