Adult Self Motivation.
The husband had a pretty good idea last year. For each unpleasant task he completed, he rewarded himself with $1 to $5 (depending on the task). He could then use that money to buy photo gear.
In general, he could just go out and buy things he wanted. But there is always that guilt factor; we keep thinking "I should save that money." By completing an unpleasant task, he has earned that reward.
Eventually, this little bit of incentive can help build a habit of doing those unpleasant things that still need to get done.