Assuming you have a visa, most immigration and border officials are efficient and tourists rarely get too much hassle. Land borders can take longer if you’re on a bus or train. Women need to be adequately covered from the moment they get off the plane or arrive at the border. Arriving without a visa is risky, as the visa-on-arrival process sees a lot of people rejected.
Contrary to popular belief, Iranian formalities are fairly relaxed about what foreigners are carrying. You are allowed to import duty-free, 200 cigarettes and 50 cigars, and a ‘reasonable quantity’ of perfume. You’ll probably allowed with any book. You should have no trouble bringing in your laptop, smartphone, shortwave radio, iPad and video equipment. Visitors are supposed to declare cash worth more than US$1000.
Officially, you can take out anything you legally imported into Iran, and anything you bought, including handicrafts other than rugs up to the value of US$160, as long as they are not for ‘the purpose of trade’. Many traders will undervalue goods on receipts issued to foreigners. A ‘reasonable number’ of rugs can be exported with no limit on value. You can also take out 150g of gold and 3kg of silver, without gemstones. If you want to exceed these limits, you will need an export permit from a customs office. Officially you need permission to export anything ‘antique’ (i.e. more than 50 years old), including handicrafts, gemstones and coins.