When purchasing patterns for my guys, I look at the same things as I do for myself and Little Miss. How many ways can I use the pattern? Are their multiple size ranges? Can I wait and buy it on sale?
For the guys, I have a few basic patterns only. Sleep pant patterns often come with a t-shirt pattern included. With Little Man, I have the option also of making him elastic waist pants from the same pattern for him to wear during the day. Just that one pattern can provide Little Man with nearly any clothing need he may have. The sleep pants can be made long or as shorts.
Shirts are a pattern that I am getting from Buckaroo Bobbins for both Joe and Little Man. They have western shirt pattern packs with multiple styles in both the men's and boys' sizes. The size range within the pattern packs are complete for most sizes. A boy's pattern pack would carry nearly all the sizes needed until the boy grew old enough for a small men's shirt. For about $20 you would have both the boy's and men's pattern packs to add to your collection. They also carry vest, jacket, and outer coat patterns. One of our favorite patterns that I still have to purchase is the "Ranger" coat. It is a very long length duster type coat with a double layer at the top to protect in the rain. For little ones, they have the "Little Ranger" that is a duplicate to the men's version.
One of the cautions that I like to extend to those considering making their family's clothing is to pay close attention to the style. Don't invest in styles that are fleeting or trendy. These will not save you any money. Instead, go for the timeless styles that you can work with for years to come. You can easily take a basic pattern and through the fabric choices that you make, you can turn an every day style outfit into one that can be worn on special occasions.
One example of dressing up a pattern for a little boy would be the sleep pant pattern. Using flannel they are comfortable sleep pants. Using fleece they become a winter weight sweat pant. If you make the exact same pattern with an elastic waist in a nice poly/cotton fabric they can become a pair of church pants. From a heavy linen or broadcloth, the pants would make a nice everyday wear pant to play in. The trick is to sew the front seam so that there is no button closure and use elastic only instead of the drawstring elastic.
The next, and likely the greatest, expense to sewing is the fabric. For each of my patterns, I have an index card with the fabric amounts needed for Joe's & my current sizes and the next size up for the children. When summer weight fabric goes on sale at the end of the season, I could take these cards to the store and know what fabric amounts to buy for the following summer. The same applies to buying winter weight fabrics. By knowing the amounts for the next size up, I won't be short on the fabric when time comes to make their clothing. Some fabrics are used more than others. Muslin is always in supply here. Next to linen, it is likely the fabric I would find the most use for.
Sewing for the home is treated the same as clothing. I buy one pattern pack that contains as much as possible to meet the needs of that particular room. Whenever possible, I would consider checking second hand stores for old blankets, table cloths, etc., before buying new fabric. An old quilt in need of repair usually has enough area in good condition that you can cut it into pieces to use for other things. Placemats, hot pads, changing table pad, are a few ideas. If the old quilt has a cotton or wool batting, you can use it to make "momma pads" or the soaker pads to place inside of a cloth diaper to increase absorbency. Old linen table cloths can be repurposed to make linen napkins. Those old decorative bed sheets can be made into curtains, aprons, or furniture scarves. Never discount the idea of using repurposed fabric for making quilts! You can save a tremendous amount of money doing that alone.
When tossing out worn clothing that cannot be repurposed, carefully cut out the buttons, pockets, zippers, and any other notions that you can reuse in another sewing project. I remember my Grandma's old button box. I had many hours of fun in my childhood simply looking through them. She saved any notions that she could possibly use again. Sets of matching buttons were strung together on thread to make them easy to find. I learned much from observing her habits in this. Today, I find that prudence to be a money saving idea that serves me well.
The last tip that I have is one that I recently began doing. Little Miss wants a cloth doll for Christmas. I went to Mardel's Christian Book Store which has a very large selection of curriculum and teaching supplies. In the back of the store, they have a self-service copying and laminating machines available for a very low cost. I took the pattern pieces for Little Miss' doll and laminated them. This pattern is a discontinued one and I wanted to preserve it so I can use it often in the future. I wouldn't do this will all of my patterns, but those that are often used or no longer available would be good candidates for it. For a multi-sized pattern, simply trace off the pattern pieces in the size needed. If you will be making many of that item, you may want to laminate the traced off copy. Crafting type patterns are most likely the ones I would use this idea for. If you are making crafts to sell at a bazaar or craft show, certainly having a laminated copy of the pattern would be a benefit.
In closing this topic, I would mention one more thing. Always have a written record in a little notebook of what patterns you have and their size ranges. This will prevent you making a duplicate purchase later on. If there are other patterns that you are wanting to purchase, have a list and make note when you buy each one. Watch the sales. Most fabric store chains will have all patterns from a manufacturer on sale once every couple of months, alternating pattern companies in each month.