Holdall bags are probably the most useful. My calico bag pattern can be a work bag, beach bag or shopper. Holdall bags are easy to make with either one shaped piece or 5 separate pieces for back, sides, and bottom. Make crochet holdalls big or large.
Half moon shape or clutch shapes big or small. Use motifs or a solid block of crochet. Use a simple crochet button or crochet flower as a fastening, big or small.
Traditional crochet string bags are the easiest and quickest to make. Best made with chunky yarns or thick cottons. The choice of colours in chunky cottons is lovely so you can go bright or subtle.
Lined or unlined bags. A lining prevents your bag from stretching and protects intricate designs from damage by contents. Use a contrasting design for the lining to add a high end look of your bag.
Duffle shape crochet bags with drawstrings are one of my favourite styles. Use motifs or make them intarsia (colour motif) style. Intarsia bags are simple to make but take some expertise in colour changing.
Traditional granny squares make lovely original bags. Use motifs square on or diagonally.
Handbag style crochet bags have a more formal shape and look good in subtle shades or shades of one colour.
Use stripes small or large, 3 large in blended shades of the same colour create a sophisticated look. Combine different yarns of the same weight to create a unique effect.
Embossed or raised designs including surface crochet are very effective particularly on holdalls. Use raised crochet to create tartan effects.
What sort of handles do you want? Crochet, wooden or bamboo handles or round handles all look good and round handles give a retro look. If you make a holdall style crochet bag you can make and line your own crochet handles.
Crochet bags with flowers. I love raised flowers on bags. These look really pretty around the top and handles of your bag. Use the same yarn or a contrast for your flowers and pick out the colours of your bag.