Border formalities
Passports are checked at the border by both Finnish and Russian border officers. In addition, passenger visas will be checked on Russian side. Different border crossing have different practices, but usually travellers are required to fill out a custom declaration (not always on bus trips) and a migration card. Migration card has two parts; one of which needs to be kept safe through the whole journey. Traffic in the border may lenghten border formalities by 2-3 hours when travelling by own car.
If you are traveling by your own vehicle, you need temporary permit from customs officials. Russian customs rarely check your baggages and belongings. Finnish customs sometimes performs intensive inspections for travellers coming from Russia to Finland. At weekends there may be traffic jams and queues that lenghten the border crossing.