Renting in Torre del Mar splits into two markets that share almost nothing beyond the buildings: long term residential letting, all year, and holiday letting, by the day or the week in summer. Knowing which one you are in decides the price, the contract and the paperwork.

Long term

These are residential contracts under Spanish tenancy law, with a deposit that for housing is normally one month's rent, held as the fianza. Expect to be asked for identification, proof of income and often a guarantee. Demand is high, especially near the beach, and good long term flats do not sit on the market.

Holiday letting

Short stays are a regulated activity in Andalusia and properties let to tourists must be registered as such. If you are letting your own flat out, that registration is not optional. If you are renting one, a registration number is a reasonable thing to see.

Practical, in both cases

Have your documents ready before you look, including a Spanish tax number. Flats go to whoever can sign first.
Ask what the community fees cover and who pays them. In a block with a pool and a lift it is not a small figure.
Local agencies are worth using here. A lot of the stock never appears on the national portals.