Coming to the gift part, first and foremost thing I would like to stress is 'Gift' is not important for a celebration. The boosting of spirit & sweet memories are the best gifts you can give your guests as a wonderful Host.
Still sharing some ideas if you desire to gift.
Few points before you buy a gift:-
- Plan it as per your budget.
- Prepare a list of Guest whom you expect will attend the golu so that accordingly you can decide on the suitable gift for them
- Seasonal gifts
SPIRITUAL GIFTS :-
- Idols of deities
- Mythological / Spiritual stories
- Decorative items for deities (for those who conduct poojas)viz., garlands, vagamalai, throne, seat, Umbrella, Thombai, etc (you can google to see the pictures to get an idea on what they are)
- Small dresses & jewelleries for small idol of gods etc
- Brass items viz., urulis, etc.
, Umbrella :Vagamalai :
, small Urulis : 
FANCY / DECOR ITEMS :-
- A stone studded kum kum chests
- Tamboolam set or Aarati Plates [plate, kum kum, haldi, lamp (fixed) ] This will help the receiver to use for their poojas.
- Wooden covered agarbathi stand cum box (it will be nice to see the
smoke coming out of the holes, the ash falls into the box thus helps for
easy cleaning)
- Imitation jewellery sets, pendants
- Fancy Bangles
- If the guest also keeps golu, find some unique dolls & gift them or festoons for decorations
- Fancy house decor items viz., vase, fengsui dolls etc
- Thorans / door hangings
- Fruit Basket / bread Basket
- Table place mats, coasters
- Doilies
- Indoor Plants which comes in small pots
- Cosmetics
- Antique look alike pieces
- Fancy Diya sets (lamps) -will be put to use for the oncoming deepavali festival
- Christmas tree ornaments
- Books - story, good housekeeping, tips n tricks, etc.
- Home made chocolates in personalised wraps
- Kolam books
- Rangoli Powders
- Art & craft kits
- Stationery items for kids
- Recipe books (you can make your own & gift too)
- Fancy Cloth / jute bags (as a part of go green measure to help them shop)
- Your personalised art & craft gifts
I will keep updating various things as and when they come to my mind. In the meantime, you may also check the following posts on navratri / golu.
Happy Navratri
Jai mata di