Set a honeymoon budget
Before you go, agree about what you'll splurge on and where you'll skimp to avoid any possible money hassles en route. Both of you should be involved in planning.
After all, this honeymoon is for both of you. If one of you does all the work, he/she'll feel guilty if things don't go perfectly. If you don't take part in the planning, you'll probably end up dissatisfied.