I have trouble finding my coyote sets in certain conditions. On private property I could hang piece of flagging but areas where need to be hidden I drive past sets more than once.

Flagging tape is pretty easy, just dont make it big and obvious. Keep it low to the ground and short so its not flapping in the wind.

GPS

Pipe cleaners

I flag trails going into where I have sets, but not at the sets. I mix it up sometimes too, I'll hang a flag on the wrong side of a trail junction from where I'm going. I even run some nearby trails I'm not trapping on just so my tracks are as random and confusing as possible. I'll jump off my snow machine and kick out a trail 100 feet into the brush just to pee (once a guy follows a couple random foot trails that end at nothing, they're probably not gonna keep looking at everywhere I jump off)

If I feel the need to mark dryland sets I'll plant a 3 or 4 foot weed stalk within 15 feet of set if in a field area. Sometimes I will mark these with a clothes pin that has a small piece of ribbon or tape on it.

Thats a new one on me. What do you hang on a limb?

That would not be noticed.

I eventual will need to get one.

I wrap marking tape around a branch or weed. Make the mark an inch wide. No one seems to notice

With a catch circle

You talking like orange flagging tape?

Thats my 1%er.

Blue painters tape. you'll be amazed how easy it is to spot wrapped around a small weed or fence strand, but more durable than flagging tape and less obvious too. It'll be there for next season much of the time.

Onx maps on my phone. Anyone not using onx for land ownership, set marking, tracks etc. is absolutely selling themselves short. It is the most useful app I’ve ever encountered. Then go home and look at it on your computer and patterns emerge.

I mark mine on OnX just for the heck of it.

All on my property so I know where they all are
If I was trapping public I would probably use the same or some form of GPS that I could drive and be able to watch from the road

For field set locations and more open edge terrain I break off golden rod stems that are at least 3-4 ft long with a flower top still attached.Or some other local weed/stem or branch stuck in the ground.

I hammer in a rebar to get some depth to push my stem into and make sure it is secure to withstand high winds and blowing snow. Place it out of reach of the catch circle area.

If I can't find them near the set which is rare. I carry some in my truck bed for those areas that I can't find any to use.

Only in woods settings will I use flagging to help mark my sets.

Any good trapper knows where they make his / her sets or at least a very good idea in general. The only time it can be a challenge is after a snow but that is why I have learned to use the golden rod stems. They stick out obviously in a snow cover blanket to pin point your sets.

Once you have run your sets a couple trips around you should develop muscle memory. If you don't, you better keep the number of your sets to what you can handle.

Trapping corn fields this time of year can be tuff. From 2' away its hard to pick out sets. Especially if not using big pile of dry dirt. I will try using sticks in mud sticking up. Might not look 100% natural but most people will walk by.

I never mark a set.

I do however write down how many are on each property.
Smiths- 14
Johnson- 10
Etc

I do the same with snares, only there I’ll write down per location.
Smiths North Draw- 10
Smiths West draw- 6
Smiths South draw- 14

Etc

It’s really important for me as I run a pile of gear and often add and subtract and move stuff as livestock moves, sign moves etc. Trapping over long durations it can be easy to loose track of stuff without some sort of record.