Collect tiles from different stores. You will find many designs and different materials of tiles. Always show interest to go to different shops and centres and ask managers for broken tiles. They usually will give you free or with nominal charges. You can even ask your friends to help you find different types of tiles. You need to explain the theme and then accordingly buy required tiles with respect to colours and quality of material.
Different pieces to mosaic on
Start with a large piece to create trivet base. Along with creating a good trivet base, you will also need a large glass, bottles or vases, flower pots, trays, small tabletop, plant stand, tables, chairs and mirrors for creating and mixing all the pieces to create mosaic on. You can buy these things from one place as well. Thrift stores will certainly help you to buy these all items with nominal price.
Buying a bucket of tile adhesive is also a very good thing. The smaller bucket is for beginners and bigger bucket is for experienced people who know how to create a mosaic with different types of materials. You will want to make sure that the adhesive is of the highest quality as it keeps everything together properly.
Buying a hammer
Buying a hammer is also a very good idea. You can even buy a tile smashing kit to smash different types of tiles according to your desired shape. There are many different hammers that you can use, as you might even want to buy a specific hammer that is designed for this purpose.
Getting grouting materials
Go to a local grouting material from a home improvement store. Buy the material which you required. Usually you need to have two 2-gallon buckets. One is for water/sponge and the other is for grout.