Are you coming to the Costa del Sol for a few days just to relax and unwind and of course get a tan? If you are then be careful about how much you pack in your suitcase along with what you pack. If you are not careful it could end up costing more than you originally thought.
Certainly if you are intending to come to Spain for a long weekend then a small suitcase with wheels should suffice in which your clothes can be carried. Plus another small bag should be carried that you keep the essential items you need with you. But remember than you shouldn't pack any kinds of bottles in this.
Also make sure that any prescription medications you need to take are packed in your suitcase in their appropriate bottles. But if you should need any of these during the flight or before or after it lands then put what you need into a small bottle or pill case in your carryon luggage.
When it comes to clothes you will find that you won't need that many items. Of course make sure that you pack several tops, some shorts and trousers. As for us women don't forget to include a couple of skirts and a dress. Then of course also pack in a couple of pairs of shoes. One pair that you can wear when out and about during the day another pair for when going out in the evening.
Finally of course make sure that you include your Passport in your luggage and remember to carry this at all times when visiting Spain. Not only will you need to use this as proof of who you are when paying for goods on a credit or debit card, but by law all visitors to the country must carry theirs at all times.