I have been using a hot glue gun on the bigger stuff but I see this could be tricky with people and other small scenery, not to mention the glue strings that is left behind with it. What do you use.
Try some white glue. Then if you wish to remove or place them somewhere else you can moisten the base and move them.
Walther's Goo. Get a fresh tube though. I've had a couple dozen figures, baggage carts and other small details glued to a module for several years and they stay in place. Goo also remains flexible, and it can be easily removed.
Securing details Since 1/2 of my NTrak module set travels upside down (or both sideways ), for people I want to stay on them, I drill a small hole up through their foot and into their leg and superglue a .015 brass rod into them. A larger hole is drilled into the module, filled with white glue and the brass rod inserted into it. Once dried, they don't move (and no glue blobs)! For other details, the brass rod is superglued to an inconspicuous (sp?) area on the detail and painted over. When painted, the brass rod usually disappears (at standard viewing distance). For the heck of it I tried the same thing with an automobile, but used a toothpick instead of the brass rod (since I had plenty of room) in the middle of the auto. That thing won't budge!
ACC For many years I have had great luck with ACC. Get some of the thick stuff, put a drop on a piece of small scrap, grab your figure on the head with a pair of tweezers (I like the large ones with the red plastic coating on the jaws), dip the figure's feet on the drop of glue and place it where you want. Spay the figure with some quick set and you're done. I have never had a figure fall off, even with traveling modules, unless it was bumped by someone.
I use white glue or Elmer's School Glue in a pinch, and occassionally super glue. With the exception of the "Starter Layout" my layouts don't travel but I can certainly understand the more bulletproof measures described above!
Try Elmers Washable School Glue Gel - it's blue, works pretty well, especially if you want to break the seal and move an object. You can probably find it just about anywhwere and it's fairly cheap.
I use Woodland Scenics Accents, too. It works quite well. But I've had trouble with keeping horses upright (since they have such teeny tiny little hoovsies!), especially the "3-legged" versions. I'm definitely going to try the suggestion about brass rods! Thanks, Dave.
>>with n-scale people? What kind of rod?<< Yep, have 1/2 doz figures permanently on the module. Standing figures get holes in their feet and legs. Sitting figures are superglued to chairs,etc, or get holes in their...ahh..you get the idea Had to go back and measure the rod on the picnic table I'll be putting on and it turns out to be .010 brass rod (might be bronze, can't be sure- bought many years ago) that I use to make handrails for storage tanks and industrial walkways.
This sounds like a good idea for a more permanent attachment. I use bees wax on my permanent layout figures.
I have been using the Woodland Scenics Accent glue with very good results on my home layout. It is forgiving if you bump a person or detail part while running trains. For N-Trak or T-Trak where lots of moving takes place, it does not hold up as well. I have been re-gluing rather than risk breaking off legs. Dave Cache Valley & Northern RR
4th vote for WS Scenic Accents! I like to put a tiny dab on the foot of the model, and on the ground where the model will be glued, let it turn clear first, then stick it in place.
A cheaper alternative to scenic accents glue is at Wal-mart. It comes in a pen it's for scrapbook pictures and whatnot. It's called 2 WAY GLUE- in a blue pen applicator. Its a sticky movable type glue. So you can re-arrange things in the future.
I have used Elmer's white. I have seen endorsements for using embalmer's wax, but have not used it myself. I also don't know where to order it and have no inclination to go to an undertaker and get some.