In a nutshell. You need some boot manager. Make at least two primary partitions and one more for backup (it can also be another drive). Install DOS 6.22 on 1st. Make a Ghost image file of it on a backup partition. Now you can delete it or make clean install of Win95 on the same partition. After install also make a Ghost image file to the backup partition. At this point you can just reghost the DOS622 on the 2nd partition (or on 1st if you like that order - it doesn't matter, but if you do this, than you'll have to reghost Win95 image on the 2nd partition). After this you have a bootable system from the 1st partition. Now you install some MultiBoot manager (OSL2000, Acronis Boot Manager, GAG... that supports primary partition hidding - I usually use GAG) and make a boot menu for the both systems.

install PLOP as a bootmanager, you get to hide unused partitions and each OS thinks it has the disk on it's own... I use it for DOS/98SE dual boot and works great.
http://www.plop.at/en/bootmanagers.html

blakespot wrote:

Would I need LILO, or is there something else?

Obviously there are other bootmanagers that can hide partitions automatically at boot time, but LILO does work. In my experience (mostly with W98SE) LILO is not the sticky wicket ... it's getting Windows to install without trashing the partition table or other partitions.