Prefocus camera place on semi stable location (backpack/table/rock, sheep, ...) use a 2s or 10s timer
trigger camera and step back Survival of camera depends on stability of sheep etc.
Or on the ground. The ground is often nice and stable. Not always.
Shop shelf or Ground or Ground? - this was 10 second timer on table or similar - probably self timer on table maybe not. Ground verticalHold camera by outer end of lens and use eg 2s timer. With practice you'll get photos from slightly further away, but not far enough at 50mm + APSC (I just tried).
Use a mirror. Yes, that's cheating, but it works. Maybe not quite like this , but it gives the idea.
Use a low cost low quality front of lens add on. These are usually not suited to quality photos but often good-enough for trip-record / fun self photos. Playing with various lenses intended for other purposes may turn up something that works 'well enough'.
Buy a really really really awful tripod - the sort that sell for about $US7 equivalent in NZ. These will mount a DSLR but as a atripod for normal use they are ultra marginal. As a tripod when you have no other and MUST have one they are still marginal, but may be better than nothing.
As a short DSLR selfie stick they may suffice BUT be sure to use the camera strap as an 'arrest' should the camera fall.An only slightly dearer tripod can work quite well.
BUT - 50mm really is not what you want to use.
Here are quite a few mostly-arm-unseen [Old Grey Guy](http://bit.ly/OldGreyGuyOld Grey Guy <) images.
Some are obviously not hand held by me - most are. That's at 17mm APSC in most cases. At 50mm you only get 17/50 = 34% as long sides and area is 34%^2 ~= 12% of the area at 17 mm !!!!