Dress for the Elements - remember rain coats, river shoes, sunglasses or whatever else your child may need for the weather that day. Warm and dry kids are happy kids.
Consider Age and Endurance - the younger the child, the shorter the attention span. Seek activities with BIG payoff from only little effort. Choosing short, semi flat hikes with a special feature like a lake, waterfall or something else to keep the kids focused on gives them a goal and keeps them wanting to go on more adventures in the future.
Play Along - for kids, the excitement is all about just being out in nature - the journey is just as fun as the destination, so try to remember that raw excitement about nature and play with your kids. If after a bit of walking down a trail, the excitement wears off, have a few games like a scavenger hunt (or animal scat hunt), I spy, the alphabet game or even a magnifying glass up your sleeve!
Give it Time - adventures with kids happen at a much slower pace than you may be used to. They like to find sticks, look at leaves, take lots of water breaks and spend time playing in the dirt. Encourage creative exploration and plan for enough time to really let your kids delve into discovering nature. And remember, it's about the journey so don't get in a hurry and rush to reach the destination.
Fuel Up - Eat a great meal before heading out and pack snacks to fuel you (and the kids) through the adventure. Let the kids get involved in choosing, packing and carrying their own light snacks on adventures. Give them their own kid sized water bottle and snack filled pack.
5 Tips for Outdoor Family Adventures by Tristin Rieken at https://freshflavorful.com/2017/10/getting-nature-kids-nooksack-falls-glacier-wa.html