Crossing stiles, streams and stepping stones steadily
Each of these obstacles asks for a step onto something narrower, higher or wetter than the path before it. A steady sequence helps, and so does knowing when not to cross.

How do you cross a stile, a stream or a line of stepping stones safely? Slowly, with your weight placed deliberately, with a hand free for support, and with a clear decision to turn back or find another way if the crossing looks wrong. Stiles reward a tidy sequence of movements. Streams and stepping stones reward patience, and the best crossing is sometimes the one you do not make.
Each of these obstacles asks the same thing of your body: a step onto a surface that is narrower, higher, wetter or less predictable than the path before it. A few Tai Chi ideas about placing the foot, testing before committing and keeping the weight clear of the ground you are leaving apply neatly, and they are worth having in mind before you reach the obstacle.
Stiles: a sequence, not a scramble
Ladder and step stiles are common on footpaths, and many are old, uneven or worn smooth. Before you start, look at the whole thing. Are the steps firm? Is the top rail sound? Is the ground at the foot of it muddy or sloping? A stile that looks rotten, loose or badly placed is a reason to look for a gate or another way over, and to tell the landowner or local authority afterwards.
Take off a pack hip belt that might catch, and if you have poles, hold them together in one hand or pass them over first so that the other hand is free. Place a hand on the top rail or post, step up with one foot onto the first tread, and bring your weight fully over that foot before lifting the other. Then repeat on the way down, facing the way you are going or sideways, whichever feels more stable.
Coming down is where most missteps happen, because the drop is hidden and the ground beyond is often churned up by cattle or boots. Lower your weight onto the leading foot rather than jumping, and treat the landing as another step, not the end of the obstacle. For help with soft landings and the order in which weight moves, walking downhill without fighting gravity covers much the same ideas.
Dogs, children and heavy bags complicate a stile. Lift or pass them over first, rather than carrying them as you climb, and use a dog gate or gap where there is one.
Streams: look before you step
Water makes judgement harder. Depth is difficult to read, especially after rain or on peaty water, and the current is usually stronger than it looks. Before crossing, study the stream upstream and downstream. A wider stretch is generally shallower and slower than a narrow one. A straight run is usually safer than a bend where the water has dug out a pool.
Your decision should start with a plain question: do you need to cross at all? Fast, brown or rising water, water above the knee, a bed you cannot see, or a current that bends the vegetation flat are all good reasons to stop and find another way. Recent heavy rain upstream can raise a stream in a short time, even if the weather where you stand is dry. If in doubt, turn back or detour to a bridge. A longer walk is a small cost.
If a crossing is small and clearly safe, such as a shallow trickle over firm stones, take it deliberately. Keep your boots on for grip, loosen your pack straps so you can slip the pack off, and face the way you are going or slightly upstream. Move one foot at a time, and do not shift your weight onto a foot until you have felt that the stone under it is steady. Poles, if you have them, can give a third point of contact, but keep the straps off your wrists so you can let go.
With every step across water, the foot goes down first and the weight follows only once the ground has been tested. If a step fails the test, nothing is lost but a moment.
Stepping stones
Stepping stones are tempting and often slippery. Algae, moss, mud and a film of water can make a dry-looking stone treacherous. Judge each stone before you step: is it flat on top, firmly bedded, and close enough that you can reach it without stretching? Is the next one in line, with space to land? If the gap needs a leap, it is too far.
Move at a steady, unhurried pace and keep your steps small. Avoid stepping on the edge of a stone, where it may tilt, and aim for the middle with a flat foot rather than the toe. Pause on each stone so your balance settles before the next move, as in why your ankles matter on uneven ground, where the ankle does a great deal of quiet work. Look ahead at the next stone, not at your feet, and keep your hands slightly out from your sides.
If the stones are underwater, wobbling, covered in weed or not clearly in line, treat the crossing as closed. The same goes if you are tired, since balance changes when we are tired, and a crossing that would be easy at nine in the morning can be a poor idea at five in the evening.
When to stop, turn back or ask for advice
Turning back is a normal part of walking, not a failure. Pick another crossing, wait for the level to drop, or choose a different route altogether when you see any of these: fast or rising water, a slippery or collapsed surface, a drop on the far side you cannot judge, a stile that is broken, or a feeling that the whole thing is more than you want to take on today.
In a group, the most cautious person's view should carry weight. Do not cross because others have, or because you have come this far. Avoid crossing in a way that leaves a child or dog able to pull you off balance.
If you are injured, cannot get back across, or are stranded by rising water, call 999 and ask for the police, and for mountain rescue if you are in upland terrain. A route-planning tool or the local access authority can often tell you about known problems with a crossing before you set off. Planning a route with a sensible alternative in mind makes the decision easier when the time comes.
Books worth reading: Knowing where you are makes a crossing easier to judge. Navigation: Techniques and skills for walkers and Map and Compass both teach the skills behind that.