There are two companies that can be very helpful here:
Vista Print https://www.vistaprint.co.uk
and CafePress http://www.cafepress.co.uk/
Vista Print often advertise on television and offer a
special code for a discount. Once you've purchased something, they often offer
you a time-limited discount on your next purchase. Take care, though, they're
very good at up-selling and cross-selling. You need a thick skin.
Vista Print is slightly cheaper but you're expected to
purchase one of your designs straightaway. However, you can have them
dispatched to a third party. So this might be useful for gifts at an online
launch. CafePress has the advantage that you can design items and leave them in
the "store". You can even get your fans to buy them. Again you can
have items sent to a third party.
Items you might consider
Postcards, bookmarks and business cards
Bookmarks are rather obvious though here's a thought.
At your event you want people to buy your book so why would you advertise it on
a bookmark you give away free? Might it not be better here to have something
about your backlist? Or about any services you offer? On the other hand, you can
often leave a stack at your local library or if your book is appropriate at
your local primary or secondary school. Take bookmarks that advertise other
books to your event.
Book front-covers fit both postcards and business cards
beautifully. Your postcard should have the front cover on one side. On
the reverse you should have the blurb, information about where to purchase the
book and a short bio. You may leave some blank space so that you can sign them
for people. I always take a heap of postcards on my school visits to give out
to youngsters who can't afford to buy the book. They often want an autograph but
if they just collect it on a scrap of paper it will probably get lost before
they've even got home. They'll be proud of the postcard and you're supplying
them and their parents with information about the book which they might buy in
the future. You might also get permission to leave postcards at local
businesses. You can use them personally as a place to write notes for other
people you meet. Keep a few with you all the time.
Business cards should have the front-cover of your book and on
the other side you should have your contact details – if only an email address
– and information about where to get the book. These can be slipped into any snail
mail you send, inside other titles you send out and used as your regular
business card.
Mugs
These are always fun and I tend to make myself one
every time I have a book out. Both Vista Print and CafePress allow you to
produce "carousel" mugs. You can have multiple book covers running
round the outside of the mug. My latest mug always becomes my default mug.
This probably won't do a lot for your sales though arguably
if you collect a few you could consider using them at an event especially if you
hold it in your own home. It's good, though, for massaging your own ego and
building up your self-esteem. It might also help you to say "I am a
writer" to the rest of your family.
T-shirts and other wearables
Yes, you wear your advertising. I've had ones made with
a front cover on the back or the front and others with lists of all my titles,
colour-coded as to whether the book is fiction, non-fiction or educational. I
wear the T-shirts to the beach and the gym or as casual summer wear. They make
a subtle impact. They remind everyone that you are a writer. And they're
T-shirts, after all, if you need them.
Pens and notepads
These do make excellent gifts, particularly at events.
The pens and the notepads are useful anyway. Every time your fans use them they
are reminded of your work and that you are a writer.
Mouse mats
You could give these to loyal fans or anyone who buys
lots of your books at an event. It will serve again as a constant reminder of
your work and that you are a writer.
Calendars
It's possible to make a calendar with a different
front-cover for every month. I once made
one like this as gift to each of the people who work with Bridge House. It was
well received.
Would this work for friends? Maybe ones who are interested
in art or in your writing?
Again, this might just be something that will help you feel
good about your writing.