Although I used checked in baggage, I managed a two-week winter stay i.e. jumpers, jeans, trainers etc... plus most toiletries for less than 20kg. Summer should therefore be dead easy as everything tends to be smaller and lighter! There was another thread about this last summer I think...
Make sure all your outfits co-ordinate colour-wise so you can mix and match. If you wear a t-shirt in the evening and dress it up with jewellery, you can then wear it another day e.g. on the beach. I try to leave them outside over night, as it helps to freshen them up a bit.
If you are flying with Ryanair, then be very careful about buying toiletries at the airport - you must be able to fit them into your
one piece of hand luggage. They are getting more strict about this, even handbags have to go inside it.
You could add one piece of checked in luggage and this would then give you 2 x 10kg hand luggage and 1 x 15kg checked luggage so overall 35kg for the two of you...?
Also, whilst toiletries are more expensive in resort, is the total cost cheaper than the baggage? You would probably pay at least £9 each way for the baggage, so can you kit yourself out with your smellies and sun cream for £18?
Louise