the habit of locking the switch or putting a small plastic disk on top of the last cell is safer.
I use small plastic tabs inserted someplace in the batteries on most of my battery operated gear. My GPS, Ham Radio, camera, Miox and flashlights all have some sort of plastic tab preventing accidental discharge. The tabs either stick out of the case with the legend "remove before use" or there is a label on the case so that if someone else is trying to use the gear they will see the label and remove it. Otherwise they may think the device is broken.
I use my battery gear a lot so most have rechargable NiMh batteries. I carry enough AA and CR123 Lithium batteries to replace all the rechargables. They weigh next to nothing and insure that I will have power when needed.
I do maintain a fairly rigid maintenance schedule on the rechargables. If they are stored without use for more than a week they are recharged and they are recharged after every use. I find this is sufficient to provide reliable use with rechargables. I could not afford to buy alkaline batteries. I use the gear a lot.
The one exception is a ham radio which has a custom lithium battery. This radio is new to me (Kenwood TH-F6) and I have not gained enough experience to work out a good technique with it yet. It has the disadvantage of lower power from the alkaline AA pack. Drops from 5 watt on the lithium to 1/2 watt on the alkaline (or rechargable) pack. This makes me want to use the alkaline pack for normal use and hold the lithium in reserve, but I have no experience about how long the rechargable lithium will maintain its charge in storage. Also not sure if repeated "top off" charging without discharging is a good idea. Anyone have experience with rechargable Lithiums?