carry a roll of orange surveyors tape with you, as you blood trail the animal tie a strip every so often about head high say every 20 or so yards, that way if you lose the blood trail stop and look back for the markers they will tell you basically which way the animal is traveling, at that time I begin a back and forth search, think like a half circle only seperate the back and forth search about 10 yards apart as you move foward enlarging the arc as you move foward. some where in there you should find blood and begin the marking again, you want to go slow and be as quiet as you can, and watch ahead of your search, THE MOST IMPORTANT THING I THINK IS WATCHING WHICH WAY THE ANIMAL GOES AFTER THE SHOT, THEN GIVE IT SAY 1/2 HOUR BEFORE THE SEARCHING. And check everything a wounded animal can and will hide where you think there is not enough cover to hide a mouse. This process has worked for me for years when trailing a shot animal.
I use toilet paper to hang on a limb above the blood
When I lose the blood I walk back to the last several pieces of paper and get a line of sight to give me a true direction of the animals trail
If I lose it from there I start making half circles arcing back and forth until I find the blood again
In the upper Midwest I would stay with the circles/spiral unless it is hilly country. I have helped other beginner hunters find their first deer using that method years ago, it worked very good - you just need patience and to pay attention and not have people in the group tromp around ahead and destroy sign - you need to inform everyone to stay behind the trackers until a patch of an area is cleared. The trackers would be me and the new hunter I was showing this method to so only the two of us moved together slowly to find the deer sign and eventually the deer. People would really get into this and it would become "the second hunt" and stories would be told after so besides being a useful skill it greatly added to the lore of their hunting experience.
A couple years back I found my mule deer with zero blood trail by using what I have learned from experience. Most of the time deer will run downhill when shot and I shot that deer (arrow) on a steep hill (mountainside) with a creek running down it. I followed the deer after a bit to where I last saw it, found no blood trail...went back up to where I shot it and found my arrow but no real blood trail. Since it started running downhill and it was steep country I cautiously started down the hill on the side I shot the deer on. I scanned visually all around and especially across the creek/draw and eventually saw my deer piled up with its antlers on the trunk of a tree preventing the body from going down farther. I crossed the creek and hiked up the short way to my deer, verified it had died and tagged it. There was no blood other than very little where the arrow exited the deer at the shot site. I was very scared i would not recover the deer in that situation but i just took a deep breath and was very careful with my work to find that deer. I was so relieved when I found him.
The rest of the late afternoon and evening was bagging quarters, etc and eventually getting a few friends to help me hike/climb the meat out of there.
So the answer is that it depends on terrain and what you know from experience you've watched game animals do after being shot.