The real challenge isn’t motivation, it’s dissuasion. Discouragement is a pernicious saboteur.
It only takes one ill-advised remark to dismantle years of enthusiasm. This is most likely to come out of your mouth when something goes wrong. And you’re not likely to notice what you said either, in fact you’ll probably feel justified.
For example, say your company conducts surveys by mail. Perhaps this process takes weeks of preparation to stuff envelopes and then weeks to process the results and input them into a database. The person responsible for stuffing envelops notices how much of a burden this is, and in passing conversation mentions that he would like to create a digital form to email to customers this year. You tacitly agree. Then, a month later, someone reviewing the survey results accidentally deletes all of the results and can’t recover them. In the moment, you’re furious and grumble loudly: “Why did we need to change things, if we had mailed the surveys this wouldn’t have happened!”
What impact do you think that will have the next time that employee sees an opportunity for improvement? Watch what you say and do that might discourage someone, rather than worry about how to encourage them.