1) Boxes are a staple for moving because they are usually quite regular sized, easy to carry and if taped together correctly, rarely fall apart. Regular sizes are important for maximizing your van space and ensuring you're not wasting areas in your transport that could otherwise be filled. On the flip side, bags can be compressed anywhere! It is possible however for bags to be mistaken for rubbish.
2) Bags are good for items like clothing, and bedding, and when you've ran out of boxes to pack anything. Teddies and soft toys work well in bags - edged objects, or items that are likely to be too heavy to carry in a plastic bag would probably work better in boxes. Bags also work well with linens.
3) Whilst packing, it’s important to maximize space - and pack your biggest objects first, and fill space around them. Books are easiest to pack, odd shaped, awkward items such as ornaments and other items are the worst to pack, and both types should go in boxes, as should dishes and other objects that are considered fragile.
4) Mark all boxes and bags (if you can) carefully - it makes them easier to find things in, and to sort into rooms without having to break them open. This will all help in your new house. Always remember to mark bags you're using for belongings clearly so that they don't get mistaken for rubbish - or buy completely different bags for your rubbish and your belongings.
5) While it may only take you a couple of weeks to pack, it can take eight weeks - or MORE to unpack at the other end - so though you're 'just boxing items up for a couple of days' remember that you may not find it for up to two months, or perhaps more.