A rule of thumb is that small safes that can be carried are less than worthless, if someone breaks in to your house they will just take the whole safe and then spend minutes or hours trying to open it back at their place. GPS tracking devices can be added to the safe however to track it after it is stolen... But who wants to spend money every month to pay for the cellular service for the tracker (best for people who keep getting robbed by the same person I guess)
But what you should do is get a shitty little safe that's just good enough that the thieves wont want to try and break into it while they're still there, forcing them to take the whole safe with them. Hopefully once they find the decoy safe they will assume that everything of yours of value is in there and leave with it without spending any more time rummaging through your shit. When they finally get it open wherever they take it to they come to find that it's full of nothing valuable, maybe some bricks (the red kind) and a bag or two of sugar. I've even heard stories about people putting hotshots in their decoy safes to get back at the asshole who steals it... However that's not the best idea since they might in turn sell it to someone else as opposed to using it themselves...
Depending on how long the thieves will spend in your place a large gun safe is best unless they bring magnetic drills and an acetylene torch and have a while to assault the safe uninterrupted. Even multi-million dollar vaults are rated by the time they can withstand the attack of a skilled safecracker, no safes are impenetrable.
Eventually you conclude that the best thing to do is to have a decoy safe and then hide all your shit in random but well concealed hiding places all over your property. That way you don't have all your shit in the same place for others to find, and if they do find one of your hiding spots, you only loose a fraction of your shit and not all of it! Another rule of thumb is that if it takes you 10 minutes to hide something, it will take someone else ten times longer to find it. If you have to take apart an elaborate contraption to access your hidden shit all the better, that's that much less likely a random asshole will think to do that when they're robbing you! Be creative! Hiding spots that involve magnets, monofiliment line, and multi-jointed reaching sticks are great too- like suspended inside a wall or halfway up a 20' AC duct... Also make sure any hidden compartments will pass the knock test, it should sound no different when knocked than the rest of the area, and if one's other hand can be reached around to the back of the area, you should be able to feel yourself knocking through the barrier (smugglers who build hidden compartments in the beds of trucks for example, are routinely thwarted by cops who knock on the metal from one side and hold their other hand on the other side- if they cant feel the vibration through the metal they know they are dealing with a hidden compartment)... Also beware of anything that can be revealed with a density meter, or a FLIR camera (i.e. a hidden door to a hidden room or stairwell may just show up as a few degrees hotter or cooler than the rest of the wall around it, due to the room temp of the hidden room being different than the temp of the wall- therefore you must get a FLIR cam like the ones the cops use and test this before hand so it can be dealt with)
Still better is burying your shit- in a non metallic container, and not in your yard- somewhere that has enough area that ground-penetrating-radar would be a timely and costly task (it only takes an hour or so to sweep a small yard with GPR, but a huge field would be beyond the patience of most people. Also obviously a metal container would set off a metal detector and that's the first thing people will use to find buried shit) A piece of SCH80 4" PVC pipe with endcaps makes a great container- it will last years and it is 99.999% airtight if it is cemented properly.
If you do intend to use your own yard however, make sure to sprinkle shake or stems and seeds or whatever all around the area randomly to throw off any dogs- a buried bag of weed or coke will eventually permeate the container and the ground, it's just a matter of time before the odor particles (which are smaller than the molecular structure of the container, and therefore pass right through) make their way up to the surface; having decoy shit scattered will render any sniffing dogs useless. This is assuming that either a) you know no one will bother with GPR, or b) you bury it so deep that it wont register on GPR... But for small stashes this is probably overkill anyway...
I'll stick with multiple, random, well-concealed hiding spots and a decoy safe! And most important is keep your fucking mouth shut!!! I know you want to show everyone how clever you are for coming up with a sweet hiding place, but the second you start telling "people you can trust" you might as well tell everyone you know. This goes doubly true for wives and girlfriends. Females are constantly following their emotions over their common sense, and the first time she thinks you're cheating (even if you aren't) all of your secrets go right out the fucking window!!!
Good Luck!