I simply use a filter paper.
Upon it drop a tiny drip of which you want to test - it then quickly soaketh in to thy filter paper. With another drip dropper, drop a single tiny drip of freshly brewed stannous chloride onto the top of thy previous drip dropped - it then soaketh into thy filter paper.
After some seconds, if positive for gold, you should see a purple ring expanding henceforth from the center. Again, the darker the ring, the more gold in solution. Gotta love those black looking blotches!
Do the following, it is very handy, especially if you want to be *really* sure everything is testig ok.
I have a very small amount of yellow gold solution in a sealed test tube for double checking the stannous is working.
Stannous seems to work best when warm, and the tiny bit of tin still fizzing in the bottom. I just recharge it with a very small pinch of tin and over a bunsen till it fizzes a bit. The bit of tin dosent even have to completely dissolve. Just give it a minute or two fizzing.
I use a glass fluted pipette for the tiny drop dripper. You dont even really need a standard big drop, just enough to wet the paper.
Have a scrap cardboard under the filter paper, (and complete workbench) so acid dont get onto things you no want acid to get onto!
It works a treat, it has plenty of room for multiple uses, and you get to keep a record of your testing. I think it might fade after some weeks/months, so take a photo! heh..