Depending on how / what you are setting up, I would typically set:
add address=192.168.0.1/23 disabled=no interface=<INTERFACE> network=192.168.0.0
add name=DHCP2 ranges=192.168.1.6-192.168.1.249
add name=DHCP1 next-pool=DHCP2 ranges=192.168.0.6-192.168.0.249
add address-pool=DHCP1 authoritative=yes bootp-support=static disabled=no interface=<INTERFACE> lease-time=1d name=DHCP
/ip dhcp-server network
add address=192.168.0.0/23 dns-server=192.168.0.1 gateway=192.168.0.1 netmask=23
While you could use a single large DHCP pool, I typically use multiple for two reasons:
1) I have run into some issues from time to time with poorly written clients choking on the .255 and .0 addresses in the middle, so I just avoid handing them out, even if they are technically valid.
2) I like to leave a 5 IP buffer on both sides of a pool, so I have static IP's reserved if I ever need them, and if for some reason I need to split them back into /24's, i don't have to rebuild as much, and keep things consistent. (i always know 1-5 and 250-254 are reserved)
Is it overkill? Probably. Has it worked great for me? Absolutely. Another thought, if this is for a network where you have a lot of turnover (public hotspots, schools, etc), try turning down the lease time to 6-8h and you will find you can stretch an address pool a lot further.