What problem does this solve?
There are always multiple ways of doing something. Members of the Wikimedia movement are accustomed to making things themselves, rather than relying on what is already there, and taking the lead instead of following others example. Planning a new project is exciting, because there are so many possibilities and opportunities. Often, during the planning phase of a new project, we choose the most ambitious and sophisticated solutions rather than simpler and more reliable alternatives. Unfortunately, this sometimes results in our projects not being completed, or project members becoming overwhelmed by the extra work necessary it takes to do everything yourself.
What is the solution?
It is important to give your project a firm foundation. When planning your project, make sure to keep your original goals in mind and consider the long-term impact of the decisions you make now about how you go about pursuing those goals. For technical projects, try to use the simplest and most reliable technologies. If you are trying to organize a community of people around your idea, consider joining forces with an existing group, such as a wikiproject with similar goals, rather than trying to build a whole new community from scratch.
Build a strong technological foundation
Choose technologies that you have expertise in and access to. Don't expect to learn a whole new programming language, or to be granted admin privileges just to complete your project. The WikiSource Individual Engagement Grant project team initially included tasks in their proposal that required close collaboration with Wikimedia Foundation engineering staff. When that began to look like an unrealistic expectation, they decided to re-frame the technical side of their project to use more accessible tools such as templates, bots, and userscripts. The Wikipedia Adventure project built off of existing code used by an abandoned project, and then used a bot hosted on Wikimedia Labs and publicly available datasets to send game invitations to new editors.
Building a community is a project all its own. If your project requires you to build an artifact as well, such as a software system or a data repository, the number of tasks and necessary skills can quickly grow beyond the bounds of a single person or small team. The goals of MediaWiki data browser project included both building a sophisticated web application and a community of users around that application. The tool was completed, but no community of users had yet appeared by the end of the project. 
Connect your project to other, related projects, or recruit members from other projects to participate. The Wikisource project was able to get members of several wikiprojects and Wikipedians-in-residence at GLAM institutions to contribute directly and to contribute to advising and outreach. In many cases, it may be advisable to attach your project as a small, independent part of a larger initiative, like a task force within a wikiproject. Once you have established a strong community of your own, you can move out. However, sometimes no community exists where you are, and you have to build one.
Factor in parties outside of Wikimedia
Some initiatives involve collaboration or communication with groups not affiliated with Wikimedia. A strong plan should anticipate the reception, actions, and engagement of these parties. Have alternatives to compensate for any lack of involvement so the primary goal can be met. Remember that the objectives of these groups are not the same as your project. Be aware of their objectives and help them see how your project is of benefit to them.
- Let the community know
- Expert involvement
- Fostering affinity groups
- Achievable goals
- Community impact
- Evaluating project outcomes
- Individual Engagement Grant: Elaborating Wikisource strategic vision. project proposal
- Individual Engagement Grant: The Wikipedia Adventure. final report
- Individual Engagement Grant: MediaWiki data browser. final report
- Individual Engagement Grant: Consolidate wikiArS to involve art schools. final report