Hi Kanaka Durga,
Its ought to recognize the best work at all times, irrespective of the method of rewards and recognition. Each company will differ with their own way of recognition. Since you ask for Appreciations and gifts details, Here below info may give you an insight.
For all Recognition's, ensure to have a proper period/Mode of evaluation of best work. For example, You can evaluate on a team basis/ period basis like quarter/Monthly/weekly etc. Once you set the mode, it comes for appreciations and Gifts.
All the good work should get an appreciation letter, since a word can vanish after some days, but not the write up. A gift in this appreciation is a hygiene factor, Since its presence may not carry a worthy motivation but the absence will defiantly brings up dissatisfaction.
To ensure this hygiene factor presence, tie up with a corporate gifting companies for the better tailored option of gifts. If not, You can choose some gift vouchers, organize some trips with their family, gifts of accessories etc etc.
PFA for the appreciation letter for your further reference..