“The great thing on these occasions… is to get a toe-hold on the psychology of the individual. Study the individual, and you will bring home the bacon.” --P.G. Wodehouse
And for all occasions, I would recommend said path of action. When wanting to mosey over to someone’s good side by taking them to dinner, you don’t want to take them to a steak house if they’re vegetarian, nor do you want to take someone allergic to granola to an all-you-can-eat parfait shop. They would be liable to turn their plate over above your head. In most cases one should not take people with vertigo on helicopter tours--an exception being if you do not like the vertigo-ee and wish to make this known.
Similar rules apply when gifting someone a boa-constrictor. If you have taken the advisable path of researching the matter and found out that your friend owns a pet rabbit that does not get on well with large snakes, I would recommend checking if the pet shop has a return policy. You could then call the person on the phone and proceed with the following script: Hello Miss/Sir, I am glad to have the pleasure of speaking to you today. Do you, by any chance, like chocolates? Roses? Snow globes of the Eiffel Tower? Ah, that is great! I will send one along as soon as I can. Why you ask? Well, it is not so often that I have the chance to speak to so charming a person. Oh, I also have a boa-constrictor that I will be dropping off at 3:00. Have a good day.
I hope you have been paying attention and have realized the essential part of the above speech. You can not just say you have dropped a watch in the mailbox. They may not want a watch. As a child, their pet rabbit may have met with a testy boa--an incident that could have easily been prevented if they only hadn’t been looking at their watch, and ever since the sight of a watch could bring tears to their eyes. This would hardly have convinced one to allow you to dump your excess reptiles on them. You must give them options. You must make an allowance for the psychology of the individual.